The cover drawing and article for this issue of the OBISPOENSIS was written and drawn by Alice Meyer. She was a very active member (and first Hoover Award Recipient in the 1970 and 80’s. She is the one who named our newsletter, OBISPOENSIS, and served as its editor (and typist) for the many years. She is also responsible for setting up the first successful chapter plant sales as well as recruiting our current Plant Sale Chair. She didn’t restrict herself to CNPS. She was also active in the Morro Bay Audubon to which she submitted a number of articles entitled “MEET A NATIVE PLANT’. Below is one of those articles. It was chosen since milkweeds are so important in the conservation of the Monarch butterfly and is being encouraged as a garden plant. Members of this genus serve as the primary food source for Monarch butterfly larva. While eating the milkweed leaves, the larva incorporate the milkweed toxins into their bodies and its these milkweed toxins that protect the Monarch larva from most predators.
I do need to mention a taxonomic update. In her first paragraph Alice places the milkweeds in the taxonomic family, Asclepiadaceae. This was where it was placed up until the 1990’s. Today the two families of milky sapped species [milkweeds (Asclepias) and dogbanes (Apocynum)] have been combined into the single family, Apocynaceae. Milkweeds are primarily temperate in distribution while the dogbane relatives are primarily tropical. Classical taxonomic work always accepted these two families as very closely related. Modern taxonomic studies (including DNA work) have discover the relationships to be intertwined which required their unification into a single family. A number of these formally separated but closely related families have now been combined.
MEET A NATIVE PLANT Asclepias eriocarpus
Milkweed is a perennial plant of the milkweed family (Asclepidiaceae) family. The species shown is common in the Coast Ranges, Sierra Foothills south to Coastal Southern California from 100 to 2000 ft. The species shown is Asclepias eriocarpa (as-KLEP-i-as aor-ee-CARP-a). Monarch butterflies lay their eggs on this plant. The plants are erect and sturdy from 18-36” tall, with leaves 3-4” long, in whorls of 3 or 4 leaves. These are covered with fine hairs, which make them look and feel like flannel. Stems and leaves contain a milky juice, a form of latex.
The clusters of flowers appear in May at the ends of stems between the leaves. The structure of the flowers is very unusual. The corolla is cut into 5 petals. These are turned down so the hide the calyx. The stamens stalks are joined into a tube and the five ‘hoods’ are attached to the base of the column; this is the ‘crown’ of corona, and in this species the crown is pink or purplish. It is actually the nectary of the flower. The flower and its stem is creamy white. In the center of the flower is a fleshy column or tube formed by the stalks of the stamens, capped by the stigma, hiding the two tubes of styles leading down to the ovaries.
The pollen in each anther-cell is a waxy mass of different anthers and adjacent masses of different anthers are attached to a cleft gland. This resembles tiny saddle-bags, clipped together, and if a bee catches her foot in the cleft she may pull out and fly away with two pollen masses to fertilize another flower. To do this, she must get her foot caught in the cleft of another flower.
The probabilities of a bee catching a foot in the cleft of two different flowers, first to collect the pollen sacs, then to deposit them in another flower is so remote that this is called ‘lottery pollination’. When a flower is pollinated its stem enlarges and the petals fall off. The calyx remains at the base of the downy seed pod which becomes 3 to 4” long and the remains of the hoods hang on to the tip of the pod for time. When the pod is ripe, and dry, it splits lengthwise, revealing neat rows of seeds, each with a parachute of fine hairs attached. As soon as the these hairs are dry, the seeds will fly away on the wind to be dispersed. Flowers that have not been pollinated along with their stems, wither and fall away.
-Alice G. Meyer