The Vasculum

I truly enjoy the genus Silphium . It has an exciting yet strangely cohesive range of morphological variation. From humble colonies of S. integrifolium to the stoic and lofty stems of S. laciniatum , from the cool, rough texture of S. terebinthinaceum to the dense flocculence of S. mohrii (see below), they never fail to please. Here is a veiny crowd pleaser; the leaf of Silphium compositum from northern Alabama. In the Ozarks Highlands of Missouri, I annually anticipate the lemony blooms of S. asteriscus that begin dazzling the understory of our acid upland woodlands soon after the summer solstice. Silphium asteriscus (Starry Rosinweed, if you must) occurs throughout the southern United States in acidic woodlands. When young, it produces a basal rosette of ovate to lanceolate leaves. When it bolts to flower, the leaves are alternate along the stem, as opposed to S. integrifolium which is opposite leaved (and which never produces a basal rosette). In spite of the dramatic ran...