The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

1. Commelina. Cyme sessile within a cordate or connate bract (spathe). Petals unequal. Perfect stamens 3; filaments naked.

2. Tradescantia. Bracts leaf-like or small and scarious. Petals equal. Perfect stamens 6; filaments bearded.

1. COMMELÌNA, Dill. Day-flower.

Flowers irregular. Sepals somewhat colored, unequal; the 2 lateral partly united by their contiguous margins. Two lateral petals rounded or kidney-shaped, on long claws, the odd one smaller. Stamens unequal, 3 of them fertile, one of which is bent inward; 3 of them sterile and smaller, with imperfect cross-shaped anthers; filaments naked. Capsule 3-celled, two of the cells 2-seeded, the other 1-seeded or abortive.—Stems branching, often procumbent and rooting at the joints. Leaves contracted at base into sheathing petioles; the floral one 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 pedicel before and afterwards. Petals blue. Flowering all summer. Ours all with perennial roots, or propagating by striking root from the joints. (Dedicated to the early Dutch botanists. J. and G. Commelin.)

[*] Ventral cells 2-ovuled (usually 2-seeded), the dorsal 1-ovuled.

1. C. nudiflòra, L. Slender and creeping, glabrous; leaves lanceolate, small (1–2´ long); spathe cordate, acute, with margins not united; seeds reticulated. (C. Cayennensis, Richard.)—Alluvial banks, Del. to Fla., west to Ind., Mo. and Tex.

2. C. hirtélla, Vahl. Stout, erect (2–4° high); leaves large, lanceolate, the sheaths brown-bearded; spathes crowded, with margins united; seeds smooth. (C. erecta, Gray, Man., not L.)—River-banks, Penn. to Fla., west to Mo. and Tex.

[*][*] Cells 1-ovuled, 1-seeded; seeds smooth; spathe cucullate; roots sub-tuberous.

3. C. erécta, L. Slender, often low; leaves linear; cells all dehiscent.—Penn. to Fla.

4. C. Virgínica, L. Slender, usually tall; leaves lanceolate to linear; dorsal cell indehiscent, scabrous.—Damp rich woods and banks, southern N. Y. to Fla., west to Mich., Iowa, and Mo.