Herbs, annual, unarmed. Stems prostrate, ascending, or erect, usually much-branched, pubescent. Leaves alternate, odd-pinnate; stipules present, persistent, amplexicaul, papery or membranous, striate, broadly ovate-elliptic; sessile or petiolate, petiole to 5 mm; leaflets 3, stipels absent, blade margins entire, apex mucronate, lateral veins parallel, unbranched, extending to margins, surfaces glabrous except abaxial midrib and margins. Inflorescences 1–4-flowered, axillary, reduced pseudoracemes, simple or singly branched, subtended by prophyll; prophyll similar to bract, 1 or 2, each persistent at base of axis, proximal one at base of peduncle, second proximal one at base of branch; bracts present, persistent, 4 at base of calyx, proximal 2 lateral, distal 2 opposite, larger than proximal bracts, shorter than calyx. Flowers chasmogamous and cleistogamous; chasmogamous flowers papilionaceous, 1 or 2; calyx persistent, campanulate, broadly so in fruit, strongly leafy veined, lobes 5, lobes broad, subequal to tube, adaxial 2 partly or mostly connate; corolla long-exserted from calyx, banner pink-purple, wings white, distinctly shorter than keel, keel purple apically; stamens 10, diadelphous; anthers dorsifixed; disc present inside staminal tube; ovary sessile, style glabrous; cleistogamous flowers indistinct, often absent, rudimental flower-bud, enclosed in calyx, 0–4. Fruits legumes, sessile, ± flattened, elliptic or broadly ovate to ± globose, style apex early deciduous, indehiscent, reticulate, pubescent; chasmogamous legumes 1 or 2; cleistogamous legumes 0–2 at base, usually slightly smaller than chasmogamous. Seed 1, brown, compressed, orbicular or broadly ovoid; hilum eccentric. x = 10, 11.

Distribution

Introduced; e Asia, introduced also in Pacific Islands (Hawaii), Australia.

Discussion

Species 2 (2 in the flora).

Kummerowia is most closely related to Lespedeza (T. Nemoto et al. 2010; Han J. E. et al. 2010; Xu B. et al. 2012) and is distinguished by its annual habit and unique inflorescence structure. A reduced pseudoraceme is the common basic structure of the inflorescence in subtribe Lespedezinae of tribe Desmodieae and has shown evolutionary change among the genera Kummerowia, Lespedeza, and Campylotropis Bunge (T. Nemoto and H. Ohashi 1990, 1993, 1996). The flowers of Kummerowia bear four bracts at the base of the calyx; that of Lespedeza, as well as other genera of Desmodieae, have only one pair of bracts, called bracteoles. The extra two bracts of Kummerowia correspond to a bract at the base of the pedicel and a primary bract subtending two or more pedicels (= pseudoraceme) of other genera of Desmodieae. The pedicels are inferred to be reduced in Kummerowia; the seemingly single or pair of flowers in the genus is interpreted as a reduced pseudoraceme.

Species of Kummerowia are widely planted in the southern United States for forage and soil improvement and are established ubiquitously (D. Isely 1990).

Microlespedeza (Maximowicz) Makino, which pertains here, is an illegitimate and superfluous name.

Selected References

None.

Lower Taxa

Kummerowia stipulacea, Kummerowia striata

Key

1	Stems with antrorse hairs; leaflets dimorphic, proximal blades obovate, distals narrowly obovate, apex retuse or emarginate; inflorescences with 1 chasmogamous flower; calyx glabrous; legumes elliptic, less than 1/2 covered by persistent calyx, apex rounded.	Kummerowia stipulacea
1	Stems with retrorse hairs; leaflets monomorphic, blades narrowly oblong-obovate or narrowly elliptic, apex acute to obtuse; inflorescences with (1 or)2 chasmogamous flowers; calyx lobe margins densely ciliate; legumes broadly obovate to ± globose, 2/3+ covered by persistent calyx, apex acute.	Kummerowia striata