Herbs with a creeping rhizome, sheathing petioles, and ample leaves, with parallel veins diverging from the midvein. Fls. with spathaceous bracts. Perianth adherent, irregular, of 3 circles, each of 3 parts, the inner often abortive. Stamens 3, petaloid, 2 sterile, the 3d fertile, lateral, with only half an anther. Ovary inferior, 1 to 3-celled. Seeds albuminous, embryo not in a sac (vitellus).
Genera 6. species 166, chiefly found in the tropics; They are remarkable, as an order, for the abundance of pure starch contained in the rhizomes of many species, constituting the genuine arrow root of commerce. This is chiefly obtained from Muranta arrundinacea and nobilis. E, Indies, and M, ramosissima, W. Indies. Some are cultivated for ornament.
1. THA'LIA, L. (Named for John Thalius, a German physician and author.) Flowers contained in a 2-leaved, glume-like spathe; calyx 3-sepaled, small, concave, lance-ovate; corolla 6-parted, the 3 outer segments equal, 3 inner very unequal; stamen 2-parted, the outer segment petaloid, inner slender, bearing the 1-celled, ovate (half) anther; style short, twisted, with a large, lip-shaped stigma; fruit capsular, thin, with 1 or 2 large seeds; embryo recurved. - Lvs. with long sheaths. Scape paniculate.
T. dealbata Roscoe. Lvs. ovate-lanceolate, acute and revolute at apex, rounded at base, petiole distinct, much shorter than its sheath; scape and panicle powdered; spathe of 2 very unequal lvs., 2-flowered, but usually 1-fruited, pilous; pericarp membranous, inclosing 1 large, farinaceous seed, in which the slender embryo lies distinct, bent double. - A tall, elegant plant, in marshes, S. Car. (Curtis) to Fla. Abundant in the Chattahoochee R. near Apalachicols,. Scape slender, 3 to 5 to 7fl high, bearing a large, forking panicle, with several lance-linear, deciduous bracts. Lvs. 9 to 14' by 4 to 8', often subcordate. Fls. purple, half concealed in the bracts.
2. CANNA, L Indian Shot. (Derivation doubtful.) Calyx of 3 sepals, persistent on the fruit; corolla 6-parted, with uneqnsl segments, the outer often reflexed; stamen petaloid, 2-lobed, the upper lobe bear ing the 1-celled (half) anther on its margin; style petaloid, fleshy, stigma obtuse; capsule muricate, 3-celled; seeds globular. - Handsome, evergreen herbs, with large lvs. and showy panicles, or spikes.
§ CORYTHIUM* (Gr. with a helmet.) Tube of the corolla prolonged above the ovary, with the outer segment spirally attached, and reflexed, inner segment and the stamen dilated and coroni-form; anther wholly adnate.
1 C. flaccida Roscoe. Glabrous; lvs. lanceolate, acuminate, tapering to a long, sheathing base; fls. spicate, 2-bracted; sep. erect, lance-linear; cor. tube more than twice as long as the sepals; limb of the inner petals spreading, flaccid, wavy, yellow, the outer lance-linear, reflexed; stigma obliquely dilated above, terminating the corolla tube. - A fine plant, around ponds, S. Car., Ga. and Fla. Stem 3f high. Lvs. near 2f long (including the narrow base), 2 to 4' wide. Fls. about 4' long. Caps, oval, 12 to 16" long. - This plant, with its congeners, might perhaps constitute a new genus.
§ CANNA proper. Corolla tube short or none, segments erect or spreading above, the inner not coroniform; anther free above.
2 C. Indica Rose. Glabrous; lvs. ovate, acuminate, abrupt at base; cor. tube scarcely longer than the sepals; segm. strap-shaped or spatulate, subequal, inner erect. - Often cultivated. Lvs. large, smooth and glossy, the lamina more than If long. Fls. near 2' long, red and yellow, † W. Indies.