Commelina benghalensis L.

A plant of moist and shaded places, used as fodder and sometimes as vegetable; medicinally used to cure skin inflammations, leprosy and as laxative.

Commelina benghalensis was first recognized and collected in California in 1980. The California plants are approximately hexaploid and represent a separate and much later introduction than the southeastern plants. The species is federally listed as an Obnoxious Weed.

A medicinal herb with febrifugal, anti-inflammatory, and diuretic effects.

Erect to prostrate perennial herb, 20-60 cm long, often dichotomously branched from the base, glabrous to pubescent, rooting below, often developing subterranean or concealed, whitish flowers on underground scapes developed from the lower nodes. Leaves ovate to ovate-oblong, subsessile to shortly petioled, with sheathing base, 2.5-7.5 cm long, 1.5-3.5 cm broad, entire, acute to sub-rounded at apex; petiole 4-10 mm long; sheaths 1-2 cm long, ciliate on the margins. Upper cymes 2-3-flowered, lower 1-2-flowered, sometimes suppressed. Aerial flowers blue, in short cymes subtended by spathes, maturing earlier than the subterranean flowers. Seeds rugose or closely pitted, sometimes wanting in aerial flowers.

Herbs, annual. Roots thin, rhizomes short, subterranean, bearing cleistogamous flowers produced from base of plant. Stems ascending to decumbent or occasionally scrambling. Leaves: leaf sheaths, not auriculate, often with red hairs at summit; blade ovate to lanceolate-elliptic, (1--)2--9(--11) ´ 1--3(--4.5) cm, apex rounded, obtuse or acute, pubescent. Inflorescences: distal cyme often exserted and 1-flowered, sometimes vestigial; spathes often clustered, subsessile (peduncles 1--3.5 mm), funnelform, 0.5--1.5(--2) cm, margins connate basally, pubescent. Flowers: chasmogamous flowers bisexual and staminate, subterranean cleistogamous flowers bisexual; petals of staminate flowers all blue (rarely lilac), proximal smaller; lateral stamen filaments not winged; staminodes 2--3; antherodes yellow, cruciform; pollen white; medial stamen pollen yellow. Capsules 3-locular, 2-valved, 4--6 mm. Seeds 5, brown or blackish, seeds of adaxial locule 1.7--2.5 mm, shallowly reticulate, farinose. 2n = 22.

Herbs perennial. Stems mostly creeping, ascending distally, diffuse, numerous branched, to 70 cm, sparsely pubescent. Leaf sheaths sparsely hirsute-ciliate; petiole distinct; leaf blade ovate, 3--7 × 1.5--3.5 cm, subglabrous. Involucral bracts borne opposite leaves, often several, aggregated at apex of branches, very shortly stalked, funnelform, 0.8--1.2 cm, sparsely hairy, proximal margins connate, apex acute or obtuse. Proximal branch of cincinni with elongate peduncle and 1--3 exserted, infertile flowers, distal branch longer, with several included, fertile flowers. Sepals ca. 2 mm, membranous. Petals blue, 3--5 mm. Capsule ellipsoid, 4--6 mm, 3-valved; posterior valve 1-seeded or seedless, indehiscent; other 2 valves each 2-seeded, dehiscent. Seeds black, cylindric or semicylindric, ca. 2 mm, rugose, irregularly reticulate, truncate at 1 end. Fl. summer to autumn.

Africa, Himalaya, India east to China, Japan, Malaysia.

Distribution: Tropical and subtropical Asia and Africa.

Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [tropical and subtropical Africa and Asia].

900-1800 m

Fl. Per.: June-September.

Wet places; near sea level to 2300 m.

Flowering spring--fall. Citrus plantations, fields, yards, and other cultivated and disturbed sites; introduced; Calif., Fla., Ga., La.; neotropics; native, paleotropics.

Commelina cavaleriei H. Léveillé.