COMMELINACEAE. 67 



corolla of mostly 3 membranous and deciduous or fugacious petals. 

 Stamens mostly 6, hypogynous, rarely fewer, all similar and perfect or 2 

 or 3 of them different from the others and sterile; filaments filiform or 

 somewhat flattened; anthers 2-celled, mostly longitudinally dehiscent. 

 Ovary superior, sessile or very nearly so, 2-3-celled; ovules 1 or several 

 in each cell, anatropous or half anatropous; style simple; stigmas termi- 

 nal, entire or obscurely 2-3-lobed. Seeds solitary or several in each cell 

 of the capsule. Capsule 2-3-celled, loculicidally 2-3-valved. Embryo 

 small. Endosperm copious. About 25 genera and 350 species, mostly 

 natives of tropical regi^ons, a few in the temperate zones. 



Fertile stamens 1-3. 1 CommrUna. 



Fertile stamens 5 or 6. 2. Rhoco. 



1. COMMELINA- L. Sp. PL 40. 1753. 



Somewhat succulent, branching herbs, with short-petioled or sessile leaves, 

 and irregular mostly blue flowers in sessile cymes subtended by spathe-like 

 bracts. Sepals unequal, the larger ones sometimes slightly united. Petals 

 unequal, 2 of them larger than the third. Perfect stamens 3, rarely 2, one of 

 them incurved and its anther commonly larger. Sterile stamens usually 3, 

 smaller, their anthers various. Filaments all glabrous. Capsule 3-celled. 

 Seeds 1 or 2 in each cavity, the testa roughened, smooth or reticulated. [Dedi- 

 cated to Kaspar Commelin, 1667-1731, Dutch botanist.] About 95 species of 

 wide distribution in warm and temperate regions. Type species: Commelina 

 communis L. 



Spathes not united at the base. 1- C. longiraulis. 



Spathes united at tlie base. 2. C. elegans. 



1. Commelina longicaulis Jacq. Coll. 3: 234. 1789. 



Glabrous or very nearly so; stems procumbent or creeping, 3-8 dm. long. 

 Leaves lanceolate or ovate-lanceolate, 2.5-7.5 em. long, acute or acuminate at 

 the apex, their sheaths sometimes ciliate; spathe acuminate, 1-2.5 cm. long, 

 peduncled, the 2 bracts not united by their margins; flowers few in each 

 spathe, 6-12 mm. broad; ventral cavities of the ovary 2-ovuled, the dorsal 1- 

 ovuled; capsule commonly 5-seeded (2 seeds in each of the ventral cells, 1 in 

 the dorsal) ; seeds oblong, reticulated, about 2 mm. long. 



Moist waste places, New Providence : — all tropioal and warm temperate reRious. 

 Referred by previous authors to C. nndiflora L. Creeping Day-flower. 



2. Commelina elegans H.B.K. Nov. Gen. 1: 259. 1816. 



Stems branching at the base, the branches decumbent, rooting at the 

 nodes, Avith puberulent internodes; leaves lanceolate to elliptic or oblong- 

 lanceolate, 4-10 cm. long, acute or acuminate at the apex, often rounded at the 

 base, the sheaths 1-1.5 cm. long, naked or sparingly ciliate on the margin: 

 spathes short-peduncled, glabrous or puberulent, 1.5-2 cm. long, acute: petals 

 blue or white; capsules obovoid, 4 mm. long, reticulated especially on the 

 dorsal lobe; seeds 3, smooth. 



Moist shaded situations. New Trovidence : — Bermuda ; Florida ; West Indies 

 and continental tropical America. fC. communis of Schoopf. L.\rger D.vv-flowbr. 



