28 TKIANDKIA. MONOGYNIA. 



is also a single species described as African, and another 

 discovered by Loureiro in Cochinchina. The genus now 

 consists of 23 species. Most of them produce blue flowefs; 

 the Norih American sj^ecies of a bright azure, but ex- 

 tremely evanescent. It is said that the Japanese possess 

 a method <3f extracting the colour from the flowers of the 

 Commelina. 



39. SYENA. TrUld. Mayaca. Jublet. 



Calix deeply 3-parted, acute, persistent. Pe- 

 tals 3, roundish. Anthers oblong, 2-celled. Stig- 

 ma trifid. Capsule acuminated with the style, 

 1 -celled, 5-valved. 



A small sub-aquatic, repent herb, resembling moss; the 

 leaves alternate, crowded, linear, subulate, (somewhat 

 Snerved, Aublet.); flowers solitary, axillary and re- 

 mote, the peduncle bending downwards after flowering, 

 (pedicell bibracteate, Aubl.) In the Stje?ia,a.s it appears 

 in the United States, the stem is bi-fistulous (for floating) 

 as in the Calitriche, the leaves each with a single nerve; 

 the peduncles without bractes, but furnished at the base 

 Avith a single valved scariose spatha; filament and an- 

 ther united, the latter shortly obovate, 2-celled, emitting 

 the pollen by 2 terminal oblique pores; style simple; stig- 

 ma entire, pei*sistent; capsule oblong-ovate, 1-celled, 3- 

 valved; seeds 9, attached by 3s to the centre of each 

 valve, spherical, acute at one of the ends, longitudinally 

 traversed by elevated scabrous lines, of a hard and brit- 

 tle consistence, and a dark brown colour. 



This is probably distinct from Aublet's plant. Existing 

 as far to. the North as Virginia. 



40. LEPTANTHUS. Mchaux. 



Spatha 1 to 4-flowered. Corolla, tube long 

 and slender; border 6-parted. Stamina seat- 

 ed upon the segments of the corolla. Anthers 

 linear, or of 2 different forms, the other trian- 

 gular. Capsule inclosed in the spatha, and in- 

 vested with the marcesent tube of the corolla, 

 S-celled, many-seeded, opening at the angles; 

 dissepiment contrary. 



Aquatic herbs, nearly allied to the genus Pontederia, 

 having alternate leaves with a sheathing base, flowers 



