Desmodium obtusum
| Desmodium obtusum | |
|---|---|
| |
| Photo taken by Kevin Robertson | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta - Flowering plants |
| Class: | Magnoliopsida – Dicotyledons |
| Order: | Fabales |
| Family: | Fabaceae ⁄ Leguminosae |
| Genus: | Desmodium |
| Species: | D. obtusum |
| Binomial name | |
| Desmodium obtusum (Muhl. ex Willd.) DC. | |
| |
| Natural range of Desmodium obtusum from USDA NRCS Plants Database. | |
Common name: stiff ticktrefoil
Contents
Taxonomic notes
Synonyms; Desmodium rigidum (Elliott) A.P. de Candolle; Meibomia rigida (Elliott) Kuntze
Description
Generally, for Desmodium genus, they are "annual or perennial herbs, shrubs or small trees. Leaves 1-5 foliolate, pinnately 3-foliolate in ours or rarely the uppermost or lowermost 1-foliolate; leaflets entire, usually stipellate; stipules caduceus to persistent, ovate to subulate, foliaceous to setaceous, often striate. Inflorescence terminal and from the upper axils, paniculate or occasionally racemose; pedicel of each papilionaceous flower subtended by a secondary bract or bractlet, the cluster of 1-few flowers subtended by a primary bract. Calyx slightly to conspicuously 2-lipped, the upper lip scarcely bifid, the lower lip 3-dentate; petals pink, roseate, purple, bluish or white; stamens monadelphous or more commonly diadelphous and then 9 and 1. Legume a stipitate loment, the segments 2-many or rarely solitary, usually flattened and densely uncinated-pubescent, separating into 1-seeded, indehiscent segments." - Radford et al 1964.
Specfically, for D. obtusum species, they are "erect perennial; stems 0.5-1.2 m tall, densely uncinate-pubescent. Terminal leaflets oblong to ovate or elliptic, (0.8) 2-3.5 (4.5) cm long, mostly 1,8-2.2 times as wide, short-puberulent to short-pubescent or glabrate above, sparsely to densely short-pubescent and reticulate below; stipules soon deciduous, lance-attenuate to ovate-lanceolate, 2-6 mm long; stipels persistent. Inflorescence usually paniculate, short-pubescent to pilose; petals purplish, ca. 4-6 mm long; stamens diadelphous. Loment of 1-4 weakly obovate to suborbicular segments, each 3-5 mm long, 2.5-2.5 mm broad, very slightly convex along the upper suture and broadly rounded below, densely uncinulate-puberulent on both sides and sutures; stipe about 1.5-3.5 mm long, longer than the calyx tube but shorter than the lobes and the stamina remnants." - Radford et al 1964.
Distribution
Ecology
Habitat
It is distributed widely throughout the eastern U.S. and southern Great Plains (NRCS Plants Database). Occurs in frequently burned longleaf and shortleaf pine-oak-hickory upland native and old-field communities (Ultisols), [1] FSU Herbarium), longleaf pine-turkey oak sandhills (Entisols), longleaf and slash pine flatwoods (Spodosols), and in limestone outcrops (FSU Herbarium). It is fire-tolerant. [1] Occurs in both native areas and areas with recent soil disturbance. Some seem to have ruderal-growing tendencies. Occurs on a wide range of soils from loamy sand to clayey soils; and in sites ranging from xeric to moist (FSU Herabarium). Associated species include Desmodium glabellum and Gnaphalium obtusifolium (FSU Herbarium).
Phenology
In the southeastern coastal plain it flowers from September to October and fruits from September to November (FSU Herbarium).
Seed dispersal
According to Kay Kirkman, a plant ecologist, this species disperses being carried externally by vertebrates. [2]
Fire ecology
It thrives in frequently burned (1-2 year interval) habitats and occurs primarily in high-light environments but can also tolerate partial shade (FSU Herbarium).
Conservation and Management
Cultivation and restoration
Photo Gallery
References and notes
Cushwa, C. T. (1970). Response of legumes to prescribed burns in loblolly pine stands of the South Carolina Piedmont. Asheville, NC, USDA Forest Service.
Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: June 2014. Collectors: R.K. Godfrey, John Morrill, Loran C. Anderson, A. F. Clewell, R. Kral, J. P. Gillespie; D. C. Hunt, R. Komarek, Sidney McDaniel, Samuel B. Jones, Jr., Harry E. Ahles, J A Duke; Charles S. Wallis, William B. Fox, Lloyd H. Shinners, and Eula Whitehouse. States and Counties: Alabama: Greene and Macon. Florida: Calhoun, Escambia, Franklin, Jackson, Leon, Madison, and Wakulla. Georgia: Baker, Colquitt, Grady, and Thomas. Louisiana: Bossier. Mississippi: Lamar. North Carolina: Mecklenburg and Robeson. Oklahoma: Sequoyah. Texas: Freestone.
NRCS Plants Database http://plants.usda.gov/java
Radford, Albert E., Harry E. Ahles, and C. Ritchie Bell. Manual of the Vascular Flora of the Carolinas. 1964, 1968. The University of North Carolina Press. 604-10. Print.
