Cucurbita palmata

Cucurbita palmata

Coyote melon

Bonnie’s drawing for this issue of Obispoensis is based on a picture sent to me by George Butterworth. The species, Cucurbita palmata, has many common names. The ones I found on the web include coyote melon, coyote gourd, desert gourd, palmate-leafed gourd, coyote ear, buffalo gourd, stinking melon, calabazilla, or chilicote.

Coyote melon is primarily a desert species that grows best where there are summer monsoons. Since we are a little north of the summer monsoon track coyote melon is relatively rare in our area. However, a few plants can be found in the eastern edge of our Chapter area (i.e., Carrizo Plain and the upper Cuyama Valley). It’s a species that prefers sandy, disturbed soils where vegetation is scarce such as desert washes and dry, rocky slopes.

The most common name around here, coyote melon, refers to its vegetative resemblance to the pumpkin, squash cucumber, melon, or gourd, family Cucurbitaceae. The Cucurbitaceae are non-woody (herbaceous) vines with tendrils and broad, palmate-veined leaves. Flowers in coyote melon are unisexual (staminate or pistilate). In coyote melon they are large and yellow and borne solitarily in the in the axils of leaves. Fruits in the family are extremely variable and are considered unique to the family. Often it is a kind of quite large berry botanists call a pepo. Pepos have fleshy, fibrous, or watery flesh inside and usually are enclosed by a clearly defined outer skin or rind. When totally mature, they often dry out to a hollow dry spheroid.

From the list of common names for the family, I suspect it would be easy to conclude that the family produces a fair number of edible and otherwise useful cultivated species. The main economic species produce edible, fleshy fruit today. But this has not always been true and is certainly NOT true of coyote melon and most other wild members of the family today. The flesh of coyote melon is extremely bitter and if one is tempted to try to eat it, it would act as an extreme emetic. That is, it would rapidly be expelled from both ends.

So what’s the link between inedible and/or poisonous wild cucurbits of today with the edible cucurbits listed above? It is best summed up by a quote from a November 20, 2015 paper by A’ndrea Elyse Messer titled “Loss of Mastodons Aided Domestication of Pumpkins, Squash.” I actually heard (or read) about the article around Thanksgiving and decided to look it up on the Web. The quote that caught my interest was: If Pleistocene megafauna – mastodons, mammoths, giant sloths and others – had not become extinct, humans might not be eating pumpkin pie and squash for the holidays, according to an international team of anthropologists.

The article indicates that most wild cucurbits are bitter and that smaller organisms (and humans) tend to avoid trying to eat the fruit. It then notes that large mammals, such as the mastodon, have fewer bitter taste buds in their mouths so eating cucurbits shouldn’t have been a problem. The authors note that they could deduce that the mastodons were eating cucurbits because when and wherever they examined fossil mastodon dung it contained cucurbit seeds. Since the only way cucurbit seeds could get into dung is by being eaten, they concluded cucurbits were an important food source for them. Being huge animals, mastodons had to migrate over wide distances so they also concluded mastodons were major dispersers of cucurbit seeds. The researchers also found that the DNA they recovered from the seeds in the dung was more similar to wild cucurbits of today than to cultivated edible ones. Therefore it’s logical that the ancestors of the edible cucurbits were bitter.

What killed off the mastodons? A recent book titled, The Sixth Extinction, gives a possible clue. It turns out that large animals live in a very tight balance with their environment and the regular sustained loss of even a few key animals would lead to extinction in a relatively short time (a few thousand years). Early humans coexisted with the last of the mastodons. Early human hunters probably preferred to kill the biggest and healthiest animals as hunters still do today. This would mean they would have taken the breeding animals of a family or herd. When a parent is killed, often the rest of their family dies as well. So even with very modest losses of a few key animals a year, the book indicates it would lead to a slow extinction in a few thousand years.

Mastodons and the other large mammals died out over ten thousand years ago. So why do we have edible cucurbits today? The article indicates that early peoples didn’t use fresh cucurbit fruits for food, but waited until they were dry and hollow and used them for containers, noise makers (rattles) and/or fish floats. Although some species’ seeds (e.g., coyote melon) are edible when totally mature, at least some of their seeds would have ended up in their disturbed, highly nitrogenous trash heaps. So people took over from the mastodons as major seed dispersers. So cucurbits would have been become common around early human settlements. Since a bitter compound is often poisonous in large uncontrolled amounts, but medicinal in small, regulated amounts, it can be assumed that early peoples used fleshy immature fruits as medicine. It doesn’t seem to me to be a great stretch to assume enough genetic variability in early cucurbits so that some would have been less bitter. These would be selectively utilized by early people, probably the wives and mothers.

By the time the mastodons were gone, early peoples would have been planting various cucurbits around their settlements. Once there, they would have been selected to be less and less bitter until we have the edible squash and pumpkins we enjoy today. So next Thanksgiving, remember to thank the mastodons and other large extinct mammals for your pumpkin pie. One final thought, pumpkins and squash were domesticated in the new world and in all likely hood the jack-o-lantern pumpkin was one of the few major crops domesticated within the lower 48 states. Personally, I find coyote melon to be best (and safely) enjoyed as we find it, growing in nature.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.
Quercus Kelloggii

Quercus Kelloggii

Kellogg Oak

The following is an article from February 1993. It was chosen by the editor to spare me the choice since Bonnie and I were away in late October. We totally agree with his choice; we had totally forgotten about it. The repeat of this article reminds me that many species of oaks have been producing fewer and fewer offspring primarily due to habitat modification and outright habitat loss. They are also probably being impacted by rising temperatures due to global climate change. It is also important to remember that oaks have been extremely important in the history of the human race. Various oak species have provided food, cork, charcoal, and lumber. A few species still do.


Dried Leaf Retention in Black Oaks

The idea for the cover was hatched out of a statement made by Bonnie while we were traveling to Yosemite Valley just before Christmas. She remarked that the dry, brown leaves and black trucks of the Sierra black oak (Quercus kelloggii) made a beautiful counterpoint to the white snow. This got me to thinking about the advantages that might accrue to a tree to keep its old, dead, dry leaves until spring of the following year. I had noticed this same phenomenon first in the eastern black oak of my youth in Illinois (Quercus nigra). Two ideas came readily to mind. First, it might provide some advantage to the plant that would aid its survival in the Montane Mixed Coniferous Forest where the Sierra black oak most often occurs. Some herbaceous plants produce hard leaves (e.g., bracken fern, Pteridium aquilinum) that last through the winter; these have been shown to shade out seedlings of competing plants during early spring growth. Last season’s bracken leaves begin to break down shortly after the new, young shoots get a foot or so tall. However, it is hard for me to accept a similar explanation to account for trees retaining dead leaves. I can think of a number of disadvantages such as increasing wind resistance and holding more snow on the branches. Both should result in more broken branches.

Retaining dead leaves could merely be an artifact of its history. Its closest relatives are all evergreen oaks and include the island scrub oak (Q. parvula) and the coast and interior live oaks (Q. agrifolia and Q. wislizeni). This group of oaks is called the red or black oak group (Erythrobalanus) and differs from the other major group, the white oaks (Lepidobalanus), primarily by having the leaf veins extending beyond the margin of the leaf as fairly heavy, tawny bristles or spines, possessing dark gray to blackish smooth bark, having thin flat acorn scales, generally taking two years to mature their acorn (exception the coast live oak) and having reddish-brown wood.

A third group of oaks is also found in California and these possess characters in combinations not found in the two major groups. All three groups include species of evergreen and deciduous oaks, but, as far as I know, only the deciduous black oaks retain many of their dead leaves for so long a time period.

Could it merely be a trait indicating a relatively recent origin of deciduous habit from the more general evergreen habit of the group? If my memory serves me right, both eastern and Sierran black oak leaves seem thicker and more leathery than one would expect for a deciduous tree.

What about the advantage of flowering trees and shrubs from evergreen habit? Primarily it is due to the fact that the off season (cold and/or dry) is not always so cold and/ or dry as to preclude a leaf from functioning. There are short periods, even in the most severe of seasons, when conditions are favorable for metabolism and growth. Evergreen plants can take advantage of these short periods because their leaves are in place, whereas deciduous trees must forgo them since, by the time they could produce new leaves, the favorable period would have been long gone.

Of course, evergreen plants must pay the cost of maintaining and protecting these living leaves during times when conditions prevent them from functioning, a cost not required of deciduous trees and shrubs. In other words, whether a flowering tree or shrub is evergreen or deciduous depends on the balance between cost of maintaining non-functional leaves versus the gain from being able to take advantage of short periods of moderate conditions. Thus, evergreen flowering trees and shrubs tend toward coastal and/or low to mid elevations where severe conditions tend to be rare and of short duration. Evergreen conifers, on the other hand, are a different story which will have wait for another time.

Dirk Walters Illustration by Bonnie Walter

Antirrhinum ovatum

Antirrhinum ovatum

Oval Leaved Snapdragon

Drawing by Bonnie and article by Dr. Malcolm McLeod below appeared in the November, 1991 Obispoensis.  

When you read it you will see lots of similarities with our current drought situation as well as the much hoped for possibilities of an excellent rain year. Yea, el Niño! If we get the rain, we just may have a once a decade or so treat to witness. We can only hope. Malcolm was a long-time member of our chapter who served several years as out chapter president. He served many years as our rare plant coordinator.  Malcolm mentions many names of people who came to see this rare event.  They are a whose who of local last generation including naturalist-rancher Eben McMillan and botanists Clare Hardham and Clifton Smith. In 1991, the Carrizo Plains area was not yet a National Monument but a Natural Area administered by the Bureau of Land Management and the Nature Conservancy.  It’s the presence of this species, as well as  number of other plant and animal species, that aided in it being designated a National Monument in 2001 by President Bill Clinton.  

– Dirk Walters, illustration by Bonnie Walter


Cornus sericea

Cornus sericea

Creek Dogwood

For this issue of the Obispoensis, I’m going out on a limb so to speak. Since the plant is a very small tree or moderately sized shrub, that limb will prove to be slender. The plant is the red osier, creek, or as stated in the new Jepson California flora, American dogwood (Cornus sericea).

Different from flowering dogwoods

This dogwood is the ugly sister to the “flowering” dogwoods as it doesn’t have its clusters of tiny flowers subtended by the large white to pink bracts found in its beautiful sisters. The beautiful sisters include the Sierra dogwood (C. nuttalii) and the even more famous eastern dogwood (C. florida). The individual flowers of all dogwood species are small; it’s the tight flower cluster that we see. The showy difference is only the presence of the large showy bracts surrounding the flower clusters. If you don’t have the large bracts to go on, how do you know it’s a dogwood? (more…)

Atriplex patula

Atriplex patula

Spear Orache, Spear Salt Bush

As I write this article, it’s August in the year of California’s third most severe drought. There’s not much out there in bloom. So I’ve retreated to one of the few places where plants are doing anything. Yes, I’m returning to the coastal salt marsh. That is where we found the plant to be featured in this issue of Obispoensis. It’s a plant that generally doesn’t get into wildflower books but does make it into many weed books. This is because it is weedy, widespread, and its flowers are green or brown and tiny and (in our area) fruiting is relatively rare.

The plant is Atriplex patula ssp. hastata or just plain A. patula depending on which plant ID book you’re using. In our area, Atriplex patula may have two subspecies which differ, according to some identification keys, primarily by their leaf shape. Subspecies hastata is the more common and distinctive of the two. Dr. Robert Hoover in his The Vascular Plants of San Luis Obispo County states that A. p. ssp. hastata is very common around the Morro Bay salt marsh. The other subspecies, A. p. ssp. patula, according to Dr. Hoover, is rare in our area. The only location he cites is nine miles north of Morro Bay. Subspecies patula produces leaves that are narrow, oblong or lanceolate; their bases are smooth and rounded and therefore lack any backward projecting lobes or acute projecting angles. The model for this plant grows along the uppermost edge of Morro Bay salt marsh.
You probably won’t get your feet wet if you would like it find it because it grows where it will get inundated only by the highest of tides, if at all.

Spear OracheA look at Bonnie’s drawing will show the distinctly arrow-head shaped leaf blades with their conspicuous backward projecting lobes on the outer leaf blade base, making the leaf resemble a spear point or arrowhead. This shape is technically termed “hastate” by botanists. The shape of the leaf gives it its subspecies name. However, if you look again at Bonnie’s drawing, you will see some leaves that are NOT hastate but would be at home in A.p. ssp. patula. I suspect that this is the reason why the new Jepson Manual doesn’t recognize subspecies in this species. It simply refers all forms to the species A. patula.

It is interesting that they retain the common name of spear saltbush or spear orache for all appearances of the species. A word about its leaf arrangement. Most of the descriptions indicate that it is alternate but a look at Bonnie’s drawing will show the plant drawn has paired, opposite leaves prominently displayed. Look at the drawing again, and you will also find alternating leaves as well. The most technical description I found stated “Leaves alternate except the proximalmost.” I’m not sure what “proximalmost” means.

According to The Jepson Manual, it may or may not be a native plant; but a survey of the web leaves little doubt that it is a recent introduction to North America. There are two common coastal salt marsh species of salt bushes found in or near the Morro Bay salt marsh. The other species, A. watsonii or Watson’s salt bush was the plant profiled in the December 2011 issue of the Obispoensis. The two salt bushes can readily be told apart with only a casual glance at their growth patterns. Watson’s salt bush grows in flat mats that can become mounded in the center. Therefore its branches are horizontal and parallel to the ground. Spear saltbush’s branches are vertical and thus can reach a height of a foot or more. Watson’s saltbush rarely reaches a height of 4-6 inches.

Some may have noticed that I have not identified the family to which salt bushes belong. This is because taxonomy texts (and most of the web entries) place it in the Amaranthaceae while The Jepson Manual places it in the Chenopodiaceae.

Classically, before DNA sequence data, salt bushes were placed in the goosefoot family (Chenopodiaceae). When the DNA sequence data and cladistic or phylogenetic classification methodologies became available, it was noted that genera of the mostly temperate zone Chenopods and the mostly tropical family Amaranthaceae came out together but were inconclusively separated in their phylogenetic diagrams.

For example see Kadereit, et al. [2003. Phylogeny of Amaranthaceae and Chenopodiaceae and the Evolution of C4 Photosynthesis, Int. J. Plant Sci. 164(6) 959-986]. This led many taxonomists to combine the two families into one. Since the Amaranthaceae is the older name, it had priority over the name, Chenopodiaceae. Therefore, if the two families are combined, then the Rules of Botanical Nomenclature require that Amaranthaceae be used.

The classical Amaranthaceae contains only four California genera (only one of them the very widespread — the weedy pigweeds, Amaranthus). In contrast, the classical Chenopodiaceae is huge in California. It consists of at least 17 genera and many species. Although most common in deserts, it is found in many other habitats as well. In other words, the classical Chenopodiaceae contains many species that dominate many habitats in California, whereas the classical Amaranthaceae are a relatively minor component.

This raises a question that has been raised many, many times before. What is the purpose of Biological Classification? When mutually exclusive, is its highest purpose to indicate phylogeny (evolutionary relationships) or is it to aid identification (ID)? Obviously it’s best when both purposes are in agreement! The authors of the Phylogeny paper admit that the phylogeny of the genera within two families is somewhat weakly supported, I think the editors of The Jepson Manual came down on the ID side of the question. I’ll leave all of you to determine who is right.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.
Calandrinia ciliata

Calandrinia ciliata

Red Maids

Bonnie’s drawing for this issue of Obispoensis is of a plant that is found throughout the western United States as well as spreading north into British Columbia. It has also been recorded in a couple of South American countries. It is especially common in coastal California. It is generally given the common name of red or pink maids (Calandrinia ciliata) although I’ve also seen it called fringed red maids and desert rock purslane on the web.

Although common and displaying easily seen bright pinkish-red, or is it reddish-pink flowers, it is often overlooked. This is because it tends to grow with its leaves and branches flat against the ground or flat against  surrounding plants. One sees it best when looking straight down on it. This is how the photo was taken upon which Bonnie’s drawing is based. The flower in the picture has its stamens just emerging from deep in the flower. It also has to be admitted that Bonnie’s drawing portrays a phase in the life of this wildflower that is fleeting.

What has been drawn is only the initial tight spiral cluster of leaves attached to a stem less than ¼ or so inches tall. Botanists call this a basal rosette. In order for the next statement to make sense, one must remember that stems grow longer only from their tips. This growth point contain cells capable of dividing to produce more cells that can then differentiate into the various types of adult cells. (They are called stem cells in animals such as humans). This region is called the apical meristem.

In the plant drawn, the apical meristem has produced a single, just opened flower. Flowers are genetically limited to parts that are set in size and shape; once they attain that configuration they stop growing. If this is true, then the central axis of the rosette is blocked from growing taller. In order for a plant to expand, it must produce branches from the lateral meristems (found in the upper angle between leaf and the stem to which it is attached). Unlike the initial vertical rosette axis, these branches grow out horizontally and the leaves are produced far apart. Additional flowers can be produced along the sides of these branches in an arrangement (inflorescence) called a raceme. Oh, I suspect it goes without saying that these secondary branches can themselves produce more branches.

David Chipping and I had never seen this plant produce a carpet of color visible from a speeding car until this year. It was a fallow field. The color was so different from anything we had ever seen. We had to stop and take a closer look. It was a carpet of red maids. I suspect that it was able to grow in such profusion due to the drought. All the larger, showier plants were either absent or extremely stunted.

Red maids is a native plant, but it is one that actually thrives with a little human disturbance. For this reason, it
is also classified as a weed, but only a slightly nuisance one.

Some might wonder why I haven’t mentioned to which plant family red maids belong. This is because there has apparently been a recent change. In ALL my “older” reference books this species is listed in the purslane family or Portulacaceae. This family contains miner’s lettuce and the beautiful Lewisias. The old Portulacaceae was easily characterized by its only two sepals and + succulent leaves. But the new Jepson Manual recognizes all the California genera but one (Portulaca – true purslane) that were in the Portulacaceae to be now in the family Montiaceae. None of my plant taxonomy references recognize the Montiaceae so none of them indicate how to distinguish the new family from the old one. A quick perusal of the keys in The Jepson Manual did not yield any obvious distinctions. Why was the Montiaceae separated out? In systematics, any recognized taxon (order, family, genus) should be derived from a single ancestor. Such a taxon is said to be “monophyletic.” However, modern classification procedures called cladistics indicate that the genera of the old Portulacaceae separate into different clusters with different ancestors. Such a group is said to be polyphyletic and is a no-no! Unfortunately many characters used to produce modern classification systems are not readily apparent in the field or even without a well equipped laboratory as they are DNA or physiologically based.

Consistent with its weedy designation, red maids would be expected to be found in disturbed ground. And this is where it is most often found. It is especially common after fires and along trails. And, as mentioned above, it is not adverse to growing in human created fallow fields and other agricultural lands.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.


[See also:

Valley Oak Snag

We are going back into the archives for this cover of Obispoensis. The landscape is a drawing of the Shell
Creek area that Bonnie drew for the December 1991 cover. The inset is an ID drawing of the leaves and acorn of the valley oak. Why would one want to combine these two pictures? What is the relationship between the two images? What follows is a short history of my encounters with the valley oak tree that became that snag.

I first encountered what was to become the snag in the spring of 1970. As can be seen from the drawing, it stood all by itself in a grassy pasture field. The field is near the junction of Highway 58 and Shell Creek Road. The base of its trunk is drawn showing that it was surrounded by various grass species while the space beyond its drip line (shown empty in the drawing) contained carpets of wildflowers.

The difference in plant species under the tree from that away is due to what has been termed “canopy effect.” Its cause is probably due to the tree, when it was alive, being able to bring water and dissolved minerals up from deep in the soil. Since the tree was somewhat inefficient in using all it brought up, some of these minerals got deposited on the outside of the leaves. This “waste” was washed or dripped off the leaves onto the ground below. Note that the canopy effect persisted several years after the tree had died, so shade was probably not a major factor.

This canopy effect was especially evident when I first encountered the tree in 1970 — the 2nd spring after the record rainfalls of 1968-9. We don’t have any record of the living tree except memory. As can be surmised from the drawing, the tree had died and become a standing snag by December 1991. It fell over sometime
in the late 1990s or early 2000s. After it fell down, the “smaller” branches were harvested for fire wood. But the trunk and bases of the larger branches were so massive that they were not deemed worth the effort to harvest.

Here is a picture of the snag today. Valley OakI have visited the snag a number of times over the years. It might seem criminal to let all that wood go to “waste,” but I assure everyone that it is not going to waste. In the years just after it fell over, it was inhabited by termites. These were not in evidence this year probably due to the drought, although I didn’t break into it to check. However I did notice that it is being used as a roof by animals burrowing under it.

The inset is Bonnie’s drawing of Quercus lobata leaves and acorn drawn in 1981. Quercus lobata (Fagaceae) is
commonly known as valley oak, California white oak or roble. The last name (roble) was used locally in the name of city, Paso Robles or more correct, Paso de Robles, which translates valley oak pass. Any one who has traveled north on 101 will note that valley oaks are common around Paso Robles and that the city sits in a valley between two high ridges.

I will recite a few notes on valley oaks. They are the largest of our California oak trees. The trunk in the picture above is over five feet in diameter. Valley oak is a true California endemic as its natural range is restricted to the valleys and low hills surrounding the Central Valley and Inner Coast Ranges. Its acorns mature in one year and were used extensively for food by native Californians.

Because the species prefers to grow in deep, fertile valley soils, it has been severely decimated by agriculture. One reason for it current survival numbers for adult trees maybe attributed to its massive size. It was easier to plow or graze around it than to cut it down.

Unfortunately acorns and seedlings are eaten by cattle and rodents, so (as was reported in the current issue of Madrono Volume 61(1) 1-8), there has been little recruitment of new trees. The cause for this lack of survival (recruitment) to older seedlings and saplings is still controversial. I suspect several causes will be ultimately determined. The paper noted that, in their study, lots of seed and early growth seedlings were found. What ever the cause, it also effects blue oak (Quercus douglasii) which is often found upslope from valley oaks.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.
Erodium moschatum

Erodium moschatum


Erodium moschatum & E. cicutarium

I assume it is not news to anyone that California in general and the Central Coast in particular has been experiencing an extreme drought. That means that most native plants that are adapted to this situation have been in waiting mode and are not doing much of anything. One ecological category of plant that seems to be able to grow under these extreme conditions is the weeds.

What is a weed?

The best definition I know is “a plant adapted to the disturbed conditions caused by humans or their livestock.” By the way, 7+ billion humans and their livestock currently make up 98% of mammalian biomass. This is up from 0.1% at the beginnings of Agriculture some 9,000 years ago. Human habitats include yards, vacant lots, crop fields, pastures.

I suspect all of you have your own favorite definition of a weed. Bonnie came up with a new definition for a weed while she was working on the drawing for this issue of the Obispoensis. She noted that “a weed just says thank you when you put a sample in a cup of water and continues to grow as if nothing important has happened, whereas native plants tend to begin to wilt even before you can get them into water.” Weeds have a high tolerance for adverse physical condition, but most usually do not tolerate competition from other plants.

Filaree belongs to the lowest classification given to weeds as it pretty much stays out of little-disturbed native vegetation. The two species of plant discussed this time are members of the genus Erodium. They are E. cicutarium (coastal heron’s bill, red stemmed filaree, red-stem filaree, red-stem stork’s bill) and E. moschatum (white-stem filaree).

Identifying Filaree

Filaree illustrationThe illustration  is a composite of Bonnie’s new and old drawings plus an additional digital scan. The large central drawing is of a whitestem filaree that was growing under crowded conditions. Note that most of its largish compound leaves, which are attached to the stem just above the root, are orientated nearly vertically. Contrast this with the scan of the red-stem filaree that was growing in a totally open habitat without nearby plants. It has its leaves lying almost flat on the ground. This is how all filaree species (including red-stem filaree) orientate their leaves when they grow in the open.

Where to find Filaree

The two filarees are found everywhere along the coast wherever humans or their livestock have modified the land. Prize winning gardeners will keep them at bay, but not ordinary people.

These species are also found in disturbed ground in the interior, but there they are likely to share the ground with several other species of filaree. All these other species (E. texanum, E. macrophyllum, E. botrys, and E. obtusipicatum) have simple leaves. E. botrys is also to be expected along the coast.

Early Classification with Geranium

When Carl Linneaus first described the filarees, he put them in the genus Geranium. Later Geranium was split into three genera (Erodium, Geranium and Pelargonium) based on the number of male structures displaying fertile or pollen producing anthers. There are five in Erodium, seven in Pelargonium, and ten in Geranium. The rest of the flower, sepals, petals and female containing structure, gynoecium, differ only quantitatively among the three genera. There is a generalized flower and gynoecium included in the illustration. These are from an early edition of Dr. David Keil and my Vascular Plant Taxonomy text.

Common names

Of particular interest is the gynoecium. Note the bulges at the bottom. These contain the actual seeds. Then there is the very long central portion (style) that resembles a bird’s beak. It is this structure that leads to the common names that have been applied to these plants, i.e., heron’s bill and stork’s bill.

Seed Dispersal

When the seed is mature, the gynoecium begins to dry out. As it dries, it splits vertically into five parts. Each part contains a basal seed-holding portion attached to its elongate portion of the style. When fully dry, the style portion begins to coil upward with increasing speed. By the time the coil and seed have reached the top of the style, it has enough momentum to be flung into the air and away from the parent plant. Most of them will land several inches beyond the reach of the parent plant. This is the sweet zone for seed dispersal. It is far enough from the parent to prevent competition but close enough to still have a similar environment. Dispersal over long distance is very risky because the probability of a seed landing in a favorable habitat approaches zero.

Long distance dispersal among weeds is contrary to this thinking. We carry weed seeds with us and when the seed falls away from us, where is it likely to land? It will probably be in another human-dominated environment.

Oh, by the way, after the seed-style complex lands on the soil, the style portion continues to expand and coil with changes in humidity. This allows for the seed to be pushed along the soil surface for a secondary dispersal. It also can serve as a “drill” to bury the seed in the soil.

Are Filaree California Natives?

Our two common coastal filarees are not native Californians. Like most of us, their ancestors came from Eurasia. When they arrived is uncertain as they were already here when the first botanical surveys were done. When I first arrived in California I was easily persuaded that native California plants were great and the rest were terrible weeds. When I made the mistake of saying, “isn’t it a shame that there is so much filaree in this pasture,” in the presence of a rancher, the rancher quickly turned on me. He said in essence, “Thank God for filaree! It is what makes my operation profitable. Cattle (and guinea pigs) love it; it is one of the first plants to appear in the pasture in the spring and it continues to be present throughout the grazing season.” I haven’t been foolish enough to bad-mouth filaree since. Both species of filaree are not only good forage for cattle, but they also are good for human grazing as well; the web tells of people using the young spring leaves like parsley in salads and the roots in various medicinal ways.

There is one last item about filaree. It can be so numerous in grazed pastures of the interior that they can produce what appears to be reddish-pink haze coating the ground. Look for it mid-morning when they are in full bloom. You might also try to imagine how many flowers it would take to create that haze.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.
Vernal Pool with Downingia

Vernal Pool with Downingia

Vernal Pools occur where there is moderate to large sized “natural” depression with no outlet. The depression has to be large enough to capture enough rainfall to fill the pond to some depth. The water collects in the lowest point in the depression. There also must be an impervious layer under the pond that prevents the water from seeping deep into the soil. This impervious layer is usually a layer of calcium carbonate that forms where water seeping downward due to gravity is balanced by pull upward caused by evaporation. True vernal pools are a desert or semi-desert phenomenon. I suspect it goes without saying that not all temporary pools are vernal pools. For example, in San Simeon State Park there are extensive interlocking shallow pools surrounding small hillocks that are filled up by winter rains and are gone by summer. These are formed by animals that dig out the depressions and pile up the excavated dirt to form the mounds. This allows the animals a drier den during the rainy season. Back East, where it rains or snows most of the year, you will find temporary ponds that will last from many months. These are colonized by ordinary species more or less identical to those that inhabit the forest around them. Vernal pools will only last anywhere from a few days to a few weeks depending on their size and the amount of rainfall.

For the second Obispoensis of this year, we are doing a repeat of a drawing Bonnie did for the banquet cover back in 1993. We’re repeating this particular drawing because of the drought and in the hope that it will serve as sign that we really, really need rain! It was originally done in honor of Dr. Wayne Ferren’s (then Curator of the Herbarium at U.C. Santa Barbara) program entitled “Creation and Restoration of Vernal Pools at Del Sur Reserve near Isla Vista, California.” The vernal pool in Bonnie’s drawing is one that occurs off the road to leading to Cerro Noroeste from California State Highway 166. It is on a shelf in the otherwise steep slopes of that mountain’s foothills. This particular pool is a favorite stop for CNPS-SLO, especially when there has been enough rainfall to fill it.

It is when the vernal pool lasts for weeks that they become particularly interesting. For plants, vernal pools are a particular challenge. The first plants to appear are those that can stand total emersion in the water. These are aquatic plants that usually live totally submerged in the water. Because the water is going to last for a very short time, these aquatic plants must have an accelerated life cycle to get from germination to fruiting. As the pool begins to dry up, plants that can tolerate saturated soils begin to germinate in a ring just inside and upslope from the water’s edge. Again these plants have a difficult environment. They begin life with too much water and end up high and dry as the pool constricts away from them. The end result of this process is a series of bands produced by various species that get their start under different soil water conditions. This banding is easily visible in Bonnie’s drawing. One genus that is particularly typical of vernal pools Downingia. It is they that form a spectacular bluish band around the pool. Bonnie included a drawing of the flower of the common Downingia species found in this particular pond. It is Downingia cuspidata.

Bonnie’s drawing was taken from a photograph, lost many years ago, that was taken on a chapter field trip to Mount Able and Mt. Pinos. Although the person shown in the drawing is drawn much too small to be recognized, notes from the time indicate that it is Sybil McLeod who served CNPS-SLO chapter in many different ways. Yes, she was also the wife of Dr. Malcolm McLeod who was a past CNPS-SLO President, Historian, and for many years the Rare Plant Committee Chairman. To be a committee chair in this chapter usually means you do all the committee’s work.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.
Mystery Manzanita in the Elfin Forest

Mystery Manzanita in the Elfin Forest

All three of Bonnie’s drawings this time are of manzanitas. One is a repeat of the endemic rare plant commonly known as Morro manzanita or Arctostaphylos morroensis. As you will see, it is included here to serve as a basis of comparison.

The other two drawings are new. One is of a single manzanita plant (maybe a clone) that grows near the mouth of Turri Creek where the Elfin Forest group’s 3rd Saturday Natural History Hike goes when it visits the salt marsh. It is currently in flower. The last is of a species commonly called, dacite manzanita (A. tomentosa ssp. daciticola). It grows nearby in the hills above the mouth of Turri Creek.

There are two other manzanita species that could also complicate the identification of our mystery manzanita. The first and most problematic is Oso manzanita (A. osoensis). Its recorded range is further away from our mystery, but still in the Turri Creek drainage. It is recorded as occurring on higher ridges and plateaus west of Hollister Peak on sandstone or dacite outcrops.

The last possibility is the Arroyo de la Cruz manzanita (A. cruzensis). It is this species that our plant would be if we used Robert F. Hoover’s 1970 edition of The Vascular Plants of San Luis Obispo County, California, for identification because it is the only species (other than A. morroensis) recorded for the area. Dacite manzanita and Oso manzanita were not recognized by Dr. Hoover as valid names.

So which name should we apply to our unknown manzanita? All who have attended these hikes readily concluded that the new manzanita is NOT the Morro manzanita. So if it is not Morro manzanita, what manzanita is it? This question, it turns out, is not easy to answer. This is where the third manzanita drawing comes in. It represents the dacite manzanita (Arctostaphylos tomentosa ssp. daciticola) which is one of two species found growing on the dacite, a granite-like rock which is dominant rock making up the Morro Sister Peaks. Outcrops of this rock weather into thin, infertile soils.

Dacite manzanita is found only within the Turri Creek drainage. I assume most will agree that, if our unknown is not Morro manzanita, it shows a much closer, but not perfect match to the dacite manzanita.

The identification of manzanitas is not easy. First, there are many species (60+ and many subspecies and varieties) recognized as growing in California. Second, I suspect all who have even a passing familiarity with California native plants can identify a manzanita. This means the genus has an easily recognized set of characteristics. It also follows that telling its many species apart is going to be a challenge because species characters must be of necessity minutely different or technical in nature.

However, they can be divided into groups based on the length of their leaf stalks (petioles) and the shape of the leaf blade base. One group, which includes the Morro manzanita, has an easily seen but short (< 4 mm) leaf stalk (petiole) and a smooth, rounded to chordate blade base. A chordate leaf base is going to resemble the top of a valentine heart. The other group has petioles either absent or so short (< 2 mm) that they would not easily be seen unless one looks carefully. Their leaf bases also resemble the top of a valentine heart (chordate). Neither of these traits is present in Bonnie’s Morro manzanita drawing which was probably based on a plant from Montana de Oro State Park. But they are found in the other two drawings.

There are other technical attributes of course, but most of these are not visible without a microscope or hand lens. One character that does not require a microscope, but does require some “digging” is whether or not a manzanita produces a large swelling at the junction where the root turns into the base of the stem. In those that don’t produce the swelling, which includes the Morro manzanita, branching doesn’t usually begin until the main stem (trunk) is a few inches or more, sometimes up to a foot or more, above the ground surface. These are called tree manzanitas due to that single trunk.

Those that branch from the swelling below ground are commonly called shrub manzanitas. Manzanitas that produce this structure tend to form their first branches below ground which produces a bunch of stems in a tight cluster. Again this trait should eliminate the Morro manzanita from consideration because it usually begins to branch at or above the soil surface.

So if it is not Morro manzanita, which of the other manzanitas is it? The Arroyo del la Cruz manzanita, as currently defined, should range from Cambia northward. The Los Oso manzanita is reported to be a relatively tall shrub (3 to 12 feet) and is reported to be restricted to dacite or sandstone outcrops. The dacite manzanita occurs just up slope from our mystery manzanita but is also supposed to be restricted to dacite outcrops. Our mystery manzanita grows on a relatively narrow terrace well above the salt marsh and just below the foundation fill used to raise South Bay Boulevard above the Morro Bay estuary. It is growing in coarse sandy soil probably derived from the fill. It is growing with species characteristic of coastal scrub with a large compliment of weeds. That is, it is growing in a classic, disturbed, man-made habitat. Such habitats are known to allow unusual individuals such as hybrids to occur out of typical range or habitat and become established. In other words, range and habitat can’t be used to limit the possible ID.

So what is its correct identification? I’m still quite unsure. Even the Cal Poly Herbarium is not much help here. I think I could find all three possible species among the specimens within each single species folder in the Cal Poly Herbarium. I do have to admit that the differences among the three short petiolate, chordate leaf-based species depends on the often subtle nature of the kind of hairs (pubescence or trichomes) found on twig and leaf. As stated earlier, these traits require at least a hand lens to observe. I think it is safest to leave it as a mystery manzanita. Maybe, a Cal Poly Senior Project or Masters student will take on this project and find the correct answer for us.

It appears that all the species from the Turri Creek drainage are closely related, at least based on appearance. With additional modern taxonomic techniques maybe it may even be determined that Dr. Hoover was correct back in 1970 when he concluded that all (except Morro manzanita) are the same species.

P.S. After writing the preceding paragraphs, I went back out and observed the three pictured manzanitas again. This time I walked through the Elfin Forest to reacquaint myself with the variability found among Morro manzanita individuals. The plants along the Board Walk are similar to Bonnie’s drawing. But if you observe the manzanitas along the Habitat Trail that goes off the north-east curve and goes toward South Bay Boulevard, you will find that the Morro manzanitas get shorter and shrubbier and their leaves have shorter petioles and more deeply lobed leaf bases. It’s a mini-cline. In other words they begin to resemble more and more our mystery manzanita. So, I’m forced to conclude, at least tentatively, that our unknown manzanita is simply an extreme form of Morro manzanita. If so, it may be the most northern individual of the species. I conclude this in spite of all of us assuring ourselves that is was clearly different from the Morro manzanita we all had pictured in our minds. I still think there is a good student project here, however.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.