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

Fewflower Tick Trefoil


CC = 8
CW = 5
MOC = 34

© SRTurner

Family - Fabaceae/Faboideae

Habit - Perennial forb from a woody caudex.

Stems - Loosely ascending, to 50 cm, solitary or few in loose clusters, sometimes from a spreading base, unbranched or less commonly few-branched from below the midpoint, the median and basal portions sparsely pubescent with minute, mostly hooked hairs and longer, straight, downward-curved hairs, usually also sparsely hairy toward the tip.

Hylodesmum_pauciflorum_stem.jpg Stem and pulvini.

© SRTurner

Leaves - Alternate, relatively well-spaced, trifoliate, petiolate, stipulate. Petioles 2-7 cm long. Stipules 2-5 mm long, 0.2-0.5 mm wide, at maturity olive green and appressed, shed early. Leaflets with the undersurface lighter than the upper surface but not glaucous; the central leaflet 2-8 cm long, 2-6 cm wide, obovate to rhombic or ovate, angled or tapered (often short-tapered) to a sharply pointed tip; lateral leaflets 3-7 cm long, 2.0-4.5 cm wide, somewhat asymmetrically ovate (the basal side broader than the side adjacent to the central leaflet).

Hylodesmum_pauciflorum_leaf1.jpg Leaf adaxial.

© SRTurner

Hylodesmum_pauciflorum_leaf1a.jpg Leaf adaxial surface.

© SRTurner

Hylodesmum_pauciflorum_leaf2.jpg Leaf abaxial.

© SRTurner

Hylodesmum_pauciflorum_leaf2a.jpg Leaf abaxial surface.

© SRTurner

Hylodesmum_pauciflorum_pressed_leaf.jpg Pressed leaf.

© DETenaglia

Inflorescence - Loose axillary racemes and panicles, compact in flower, elongated in fruit, terminal and also axillary from the upper nodes, ascending, unbranched or with few, loosely ascending branches, the axis pubescent with sparse to moderate, minute, hooked hairs and often also widely scattered, straight, spreading hairs. Bracts 1-4 mm long, 0.2-0.3 mm wide, linear, sometimes shed early; bractlets sometimes also present, these somewhat shorter than the bracts (to 2.5 mm long), shed early. Flower stalks 2-11 mm long.

Hylodesmum_pauciflorum_inflorescence.jpg Inflorescence.

© SRTurner

Hylodesmum_pauciflorum_inflorescence2.jpg Inflorescence.

© SRTurner

Flowers - Calyces bilabiate, olive green, minutely hairy toward the base and with sparse to moderate, longer, straight hairs throughout, the tube 1.5-2.0 mm long, the lobes 0.2-0.5 mm long. Corolla papilionaceous, 5-7 mm long, white. Standard 5 mm long, glabrous. Wing petals spreading, 4 mm long, to 2 mm broad. Keel petals distinct, deflexed, same size as wing petals. Stamens diadelphous, the free apices curled. Tube white and glabrous. Anthers pale yellow, 0.2 mm long. Ovary green, pubescent, 3-4 mm long, compressed. Style glabrous and curved, 1.4 mm long.

Hylodesmum_pauciflorum_flowers.jpg Flowers.

© SRTurner

Hylodesmum_pauciflorum_flower3.jpg Flower.

© SRTurner

Hylodesmum_pauciflorum_flower2.jpg Flower.

© SRTurner

Hylodesmum_pauciflorum_calyx.jpg Calyx

© SRTurner

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_fruit.jpg Fruit

© SRTurner

Flowering - June - September.

Habitat - Bottomland and mesic forests, bases of bluffs, streambanks, pond margins.

Origin - Native to the U.S.

Lookalikes - None.

Other info. - This small species is found in scattered counties in Missouri, mostly in the southern half of the state. Beyond Missouri it is found scattered across much of the southeastern U.S. The plant is often missed because of the typically dark habitat in which it grows and its inconspicuous appearance. It broadly resembles other species in the genus but is distinguished by its pure white flowers and short stature. It often forms colonies when growing in favorable conditions, and these sometimes produce few flowers.

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 and 8-17-2020 (SRTurner).