Morphology and identification of the seedlings of selected woody/semi-woody species of dicotyledons sensu lato growing wild in South Florida (U.S.A.). Part II. Species with hypogeal germination

Abstract

Herein, I describe and compare the seedlings of 23 species which have hypogeal germination and of an additional species having germination intermediate between hypogeal and epigeal. The species are of trees, shrubs, and woody vines of dicotyledons sensu lato which grow wild in south Florida. In those species the portion of seedling stem situated distal to the cotyledons consists of two main parts: the basal stem sector and the distal stem sector. The first-formed foliage leaves develop on the distal stem sector. The basal stem sector serves to position those foliage leaves sufficiently high aboveground to intercept adequate ambient light; thus, it is functionally equivalent to the elongated hypocotyl in species having epigeal germination. Certain of the studied species exhibit cotyledons that are entirely or partly connate and/or peltate, unlike the adult leaves. For each species I characterize the macroscopical features of the diaspores, cotyledons, basal stem sector, distal stem sector, and leaves, as well as the presence vs. absence of, the kinds of, and the distribution of trichomes. I conclude with a taxonomic key for identifying the seedlings of all considered species. Twenty-two and two of the species are native to, and exotic within Florida, respectively.