Mar 8 2019
San Francisco, Cal., June 20, 1896
My dear Miss Vail:
Will you be so kind as to excuse my delay in replying to your note about that Asclepias. I have been overwhelmed with work.
In looking up that Asclepias again, I am again convinced that it is only a variety. The type does not agree exactly with the specimens that you collected in another locality. I have the type only in flower; while this I found only in fruit, but I feel sure that they are the same.
My paper on my Utah collection will soon be out and in that I have made notes of all variations. I don’t believe the ripe fruit of A. involucrata has been collected. Prof. Gray would have described it if he had obtained it. We have Dr. Rusby’s specimen collected in Arizona in 1883 and one from Prescott Ariz. collected in 1877. In both of these the umbel is terminal and there is no sign of an axillary umbel. The leaves are not clustered like an involucre as in Gray’s description in Synop. Flora.
In my type of var. tomentosa, two stems of the same plant have terminal umbels only, a third has one terminal and one axillary. I think that is not an important difference.
If we begin to make new species in this, there is no telling where it will end, because it is evidently exceedingly variable.