Hylodesmum glutinosum (Muhl. ex Willd.) H. Ohashi & R.R. Mill
Cluster Tick Trefoil
Family - Fabaceae
Stems - To 1m tall, herbaceous, pubescent (sometimes sparse), often glaucous, erect, simple, from a tap root.
Leaves - Alternate, trifoliolate, petiolate, stipulate, mostly grouped near middle of stem below inflorescence and giving a whorled appearance. Stipules 9-12mm long, -2mm broad, lanceolate, acute, pubescent. Petioles to +/-20cm long, pubescent, with an adaxial groove. Lateral leaflets on petiolules to 5mm long. Petiolule thick, pubescent. Leaflets oblique at base, ovate, acuminate, to +12cm long, +6cm broad. Terminal leaflet largest, to 15cm long, +9cm broad, ovate, apex acuminate. Petiolule of terminal leaflet to +5cm long. All leaflets pubescent (sometimes sparsely) above and below, entire, with ciliolate margins, often somewhat scabrous.
Inflorescence - Terminal panicles to +40cm long. Axis tomentose. Pedicels to 6mm long in flower, glandular pubescent, often reddish.
Flowers - Papilionaceous. Standard pink, 7mm broad and long, emarginate at apex, glabrous. Keel and wing petals glabrous, pinkish, +6mm long. Stamens monodelphous, 5mm long. Anthers yellow. Style glabrous, white, curved, 2mm long. Ovary 4-5mm long, green, cylindric. Calyx bilabiate, sparse pubescent. Calyx tube to 1mm long. Upper lip shallow, 1-lobed. Lobe to 1.5mm long. Lower lip 3-lobed. Lateral lobes small, acute. Central lobe larger than laterals, acute, 1mm long. Fruit segments typically 3-4, rounded on ventral margin, straight to slightly curved on dorsal surface to +1cm long, +6mm wide, pubescent.
Flowering - June - August.
Habitat - Thickets, streambanks, low woods, roadsides, railroads.
Origin - Native to U.S.
Other info. - This is one
of the easier species of the Desmodium / Hylodesmum complex to identify because
of the leaf arrangement. No other species in these genera has the leaves
so obviously bunched in the middle of the stem like a pancake tutu. The fruits are just as
"sticky" as the other species and will cling to any fabric.
Photographs taken at Alley Spring, Shannon County, MO., 6-27-03.