COMMELYNACEJE. (SPIDERWOKT FAMILY.) 355 



1. SMI LAX, Tourn. Green Brier. 



Characters of the order : flowers in umbels. 



1. S. rotundifolia, L. Stem armed with scattered prickles, as well as 

 the terete branches : branchlets more or less 4-angular : leaves orate or round- 

 ovate, slightly heart-shaped, abruptly short-pointed : berries blue-black, with 

 a bloom. — Colorado and eastward. 



Order 81. COMMEL.YHrACE.ffi. (Spiderwort Family.) 



Herbs, with fibrous or sometimes thickened roots, jointed and often 

 branching leafy stems, and chiefly perfect and 6-androus, often irregular 

 flowers, with the perianth free from the 2 to 3-celled ovary, and having 

 a distinct calyx and corolla, of 3 persistent sepals and as many ephe- 

 meral or deciduous (in ours blue) petals. Style one, stigma undivided. 

 Pod 3 to several-seeded. — Leaves ovate, lanceolate or linear, parallel- 

 veined, flat, sheathed at the base ; the uppermost often forming a kind 

 of spathe. 



1. Conimelyiia. Flowers irregular. Three stamens fertile and three sterile and smaller : 



filaments naked. 



2. Tradescantia. Flowers regular. Stamens all fertile : filaments bearded. 



1. COMMELYWA, Dill. Day-Flower. 



Sepals somewhat colored, unequal; the 2 lateral partly united by their 

 contiguous margins. Two lateral petals rounded, on long claws, the odd 

 one smaller. Sterile stamens with imperfect cross-shaped anthers. — Stems 

 branching, often procumbent and rooting at the joints: floral leaf heart- 

 shaped and clasping, folded together or hooded, forming a spathe enclosing 

 the flowers, which expand for a single morning and are recurved on their 

 pedicels before and afterwards. 



1. C. Virginiea, L. Stems slender, erect, or reclined and rooting towards 

 the base : leaves oblong- or linear-lanceolate : spathes peduncled, conduplicate, 

 round-heart-shaped when expanded, in fruit somewhat hood-like. — E. Colo- 

 rado and eastward to New York. 



2. TRADESCANTIA, L. Spiderwort. 



Sepals herbaceous. Petals all alike, ovate, sessile. — Stems mostly upright, 

 nearly simple, leafy : leaves keeled : flowers ephemeral, in umbelled clusters, 

 terminal (in ours) : floral leaves nearly like the others. 



1. T. Virginiea, L. Leaves lance-linear, elongated, tapering from the 

 sheathing base to the point, ciliate : umbels sessile, clustered, usually involu- 

 crate by 2 leaves, many-flowered. — From New Mexico northward and east 

 ward across the continent. 



