Hylodesmum is a genus of flowering plants in the legume family Fabaceae (order Fabales), comprising approximately 16 species commonly known as ticktrefoils or tick-trefoils. The genus was segregated from the broadly defined genus Desmodium, and some treatments still include these plants within Desmodium. The genus was formally described by H.Ohashi & R.R.Mill.
Species of Hylodesmum are herbaceous to subshrubby perennials characteristic of shaded woodland habitats. Like other members of the legume family, they produce flowers with the typical pea-flower (papilionaceous) structure, followed by lomentum-type seed pods — segmented fruits that break apart at constrictions between seeds, each segment bearing hooked hairs that attach readily to animal fur or clothing, aiding seed dispersal (hence the name "ticktrefoil").
The genus has a notably disjunct distribution, with species native to eastern North America, sub-Saharan Africa, Yemen, South and Southeast Asia, East Asia, Malesia, and New Guinea. Well-known North American representatives include H. nudiflorum (nakedflower ticktrefoil) and H. glutinosum (pointed-leaf ticktrefoil), while H. podocarpum and H. menglaense are found in Asia.
Distribution
Hylodesmum species are native to eastern North America, sub-Saharan Africa, Yemen, South Asia, Southeast Asia, East Asia, Malesia, and New Guinea — a notably disjunct distribution across tropical and temperate woodland regions.
Taxonomy Notes
Hylodesmum is sometimes treated as a subgroup of the larger genus Desmodium, and some taxonomic authorities still include its species there. The genus name and circumscription were established by H.Ohashi & R.R.Mill. It belongs to the family Fabaceae (order Fabales).
