Desmodium strictum (Pine-barren tick-trefoil)

Desmodium strictum (Pursh) DC.

Pine-barren tick-trefoil

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Rosidae	Roses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
Order	Fabales	Legumes (pea and bean families)
Family	Fabaceae	Legume family (peas and beans)
Genus	Desmodium	Fromthe Greek desmos, “bond, fetter, halter, or chain”
Species	strictum	Upright

About plant names...

This rare species is native to North America. It prefers sandhill woodlands, dune woodlands, sandy clearings, and roadsides.

Plants: Stems are erect, in groups of one to a few, with minute hairs, 20-47" (50-120 cm) in height.

Leaves: Thick, linear, 6-10 times longer than they are wide, on long stems (petioles). Terminal leaflets are 1-2" (3-6 cm) × ⅛-⅜" (3-10 mm).

Flowers: Flowers are purple or pink, on panicles 8-20" (20-50 cm) long, with flowers on uplifting tiny stems (petioles) ⅛-⅜" (6-11 mm) long.

Fruits: Fruits somewhat resemble peapods. Technically they are loments, seedpods that break apart at their constrictions but do not open to release their seeds.

Online References:

Desmodium strictum on Discover Life

Desmodium strictum on SEINet—the Southwest Environmental Information Network

References:

Weakley, Alan S.; Ludwig, J. Christopher; Townsend, John F.; Crowder, Bland (Ed.), Flora of Virginia, Botanical Research Institute of Texas Press, 2013, p. 577