Hylodesmum pauciflorum (Nutt.) H. Ohashi & R.R. Mill

Fewflower Tick Trefoil

Hylodesmum pauciflorum plant

Family - Fabaceae

Stems - Herbaceous, erect, from a woody caudex, to 45cm tall, retrorse pubescent, sparse glandular pubescent also, typically unbranched.

Leaves - Alternate, stipulate, trifoliolate, petiolate. Stipules fugacious, to 5-6mm long, 1mm broad, antrorse pubescent. Petioles to 7cm long, with an adaxial groove, 4-angled, sparse antrorse pubescent and puberulent. Swollen portion at base of petiole to 4mm long. Lateral leaflets entire, ovate, acute, oblique, green above, silvery green below, pubescent. Petiolules to 3mm long, pubescent. Terminal leaflet rhombic to broadly ovate, with a petiolule to 1.5cm long, colored and pubescent as lateral leaflets, entire, acute.

Hylodesmum pauciflorum leafPressed leaf.

Inflorescence - Loose axillary racemes and panicles, compact in flower, elongated in fruit. Axis of inflorescence glandular pubescent. Pedicels to -5mm long in flower, longer in fruit, subtended by a small subulate bract. Bract to 3mm long, -1mm broad.

Hylodesmum pauciflorum inflorescenceInflorescence.

Flowers - Corolla papilionaceous, to 9mm broad, 4-5mm long, white. Standard -5mm long, glabrous. Wing petals spreading, 4mm long, to 2mm broad. Keels deflexed, same size as wing petals. Stamens diadelphous, the free apices curled. Tube white and glabrous. Anthers pale yellow, .2mm long. Ovary green, pubescent, 3-4mm long, compressed. Style glabrous and curved, -1.4mm long. Calyx bilabiate, glandular and antrorse pubescent. Upper lip shallowly lobed, with a notch at apex. Lower lip 3-lobed. Center lobe short-acuminate, -1mm long. Loments typically 2.

Hylodesmum pauciflorum flowerFlower.

Hylodesmum pauciflorum calyxCalyx

Fruits - Loments of 1-3 segments, each 9-12 mm long and 3.5-8.0 mm wide, the upper side of each segment usually not concave.

Hylodesmum pauciflorum fruitFruit

Flowering - June - September.

Habitat - Rich, moist woods, ravines, bases of bluffs.

Origin - Native to U.S.

Other info. - This small species is found in the southern 1/2 of Missouri. The plant is often missed because of the habitat in which it lives and its inconspicuous appearance. This species resembles other species in the genus but is distinguished by its pure white flowers and short stature. It can form colonies when growing in favorable conditions.

Photographs taken at the Peck Ranch Wildlife Area, Shannon County, MO., 7-17-01, and in Brown Summit, NC., 7-12-01 (DETenaglia); also at Shaw Nature Reserve, Franklin County, MO, 6-20-2012, and Young Conservation Area, Jefferson County, MO, 7-31-2013 (SRTurner).