19. Ditrysinia Rafinesque, Neogenyton. 2. 1825.
[Greek ditry, two or three, and syn, together, alluding to number and union of stamens] [Greek ditry, two or three, and syn, together, alluding to number and union of stamens]
Kenneth J. Wurdack
Shrubs, monoecious; hairs unbranched; latex absent. Leaves semipersistent, alternate, simple; stipules present, persistent; petiole present, glands absent; blade unlobed, margins entire, laminar glands usually abaxial, scattered, sometimes absent; venation pinnate. Inflorescences bisexual (pistillate flowers proximal, staminate distal) or staminate, terminal, racemes; glands subtending each bract 2. Pedicels present. Staminate flowers: sepals 3, imbricate, connate basally; petals 0; nectary absent; stamens 3, distinct; pistillode absent. Pistillate flowers: sepals 3, connate basally; petals 0; nectary absent; pistil 3-carpellate; styles 3, connate basally, unbranched. Fruits capsules, base not persisting. Seeds ovoid-oblong; outer seed coat dry; caruncle present.
Species 1: se United States.
Molecular phylogenetic analyses indicate a close relationship of Ditrysinia with Microstachys, but taxon sampling is too sparse to determine if Ditrysinia should contain other species that are now classified in polyphyletic Sebastiania (K. Wurdack et al. 2005).