ORDER 13G. HYDROCHARIDACE^E. 679 



ORDER CXXXVI. HYDROCHARIDACEvE. FROGBITS. 



"Aquatic Tierbs with parallel-veined leaves and diclinous fls. on a slender-stalked 

 spadix. Perianth regular, 3 to 6-parted, the inner segments petaloid. Stamens 3 

 to 12. Ovary adherent to the perianth, 1 to 9-celled, with 3. 6 or 9 large stigmas. 

 Fruit dry or succulent, many-seeded, indehisent. Seeds without albumen. 



Gtnt>-fi 12, sptcie* 20. native of fresh water in Europe, N. America, E. Indies and N. Holland. 

 They appear to possess no active properties. 



1. LIIVINO'BIUM, Richard. FROGS-BIT. (Gr. Mfivrj, a lake, fitog, 

 life.} Flowers monoecious, arising from subsessile spathes ; $ spathe. 

 1-leaved, about 3-flowered, calyx 3-scpaled, corolla 3-petaled, petals ob- 

 long-linear; stamens G to 12, monadelphous ; ? spathe 2-lcavcd, 1- 

 flowered ; calyx and corolla as in the $ ; stamens 6, subulate rudiments ; 

 ovary G or 9-celled, becoming a co-seeded berry. 2 Herb acaulescent, 

 in stagnant waters, multiplying by stolons, and with floating Ivs. Fls. 

 showy, white, the $ on long stalks. 



Ii. Spoiigia Rich. In Braddock's Bay, L. Ontario (Sartwell); scarce at the north, 

 common ia the south, E. Ky. ! to Ga. (Feay) and La. (Hale). Lvs on long pe- 

 tioles, roundish, obtuse or broadly acute, often cordate, 1' to 18" diam. Fed. of 

 the sterile fls. slender, about 3' long, of the fertile, thick, about 1' long, botli 

 kinds cither together on the same stalk or on different stalks which are connected 

 by the stolons (Dr. Feay). The leaves beneath are purplish and spongy with largo 

 cells. J!., Aug. (Hydrocharis, Bosc. II. cordifolia Nutt.) 



2. AUACH'ARIS, Richard. DITCH Moss. (Gr. av, an indefinite par- 

 tide, a%apL<;, uncomely.) Flowers polygamous, solitary, from a tubular, 

 bifid, axillary spathe ; perianth 6-parted, colored ; $ minute, with 9 

 oval, ncavly sessile anthers ; ? perianth excessively produced into a 

 filiform tube above the ovary, limb 6-parted, stamens 3 to G, often abor- 

 tive 1 ; style capillary* adherent to the tube of the perianth ; stigmas 3, 

 large; fruit few- seeded. If. Small aquatic herbs, with submersed pellu- 

 cid opposite or verticillate Ivs. 



A. Canadensls Planchon. Lvs. verticillate in 3s and 4s, lanceolate, oblong or 

 linear sunulate; stig. 2-lobed. Resembling a coarse moss, in still waters and 

 bogs. St. filiform, diffusely dichotomous, very leafy. Lvs. 3 to G" by (less than) 

 1", Ihin r.nd diaphanous, sessile, obtuse. Fls. minute, of a dingy white, the slen- 

 der, hair-like tube 2 to 10' long, according to the depth of the waters. Stigmas 

 recurved between the segments, crested with glandular hairs. Aug. (Udora, 

 Nutt.) 



3. VALLISTtE'RIA, Micheli. EEL-GRASS. (In honor of Anthony 

 ValU&ncr, a French botanist.) Flowers $ $ ; spathe ovate, 2 to 4- 

 parUd. $ Spadix covered with minute flowers, enclosed in a 3-parted 

 .spathe; corolla 0. $ Spathe bifid, 1-flowered ; perianth elongated; 

 sepals linear : stigmas 3, ovate, bifid ; fruit elongated, cylindrical, many- 

 seeded. 2 Submersed. Lvs. all radical, grass-like. Scape spiral, 

 very long. 



"V. spirals L. Lvs. linear, obtuse, serrulate at the end, tapering at the base, 

 floating. A curious plant, in slow moving or stagnant waters, U. S. Leaves 

 linear, 1 2f long, about ' wide, the edges thinner than the middle. Scapes 

 several, of the sterile plants short, of the fertile plants very tortuous, 2 4f long 

 when extended, thread-like, thickened at the top, bearing each a single, white 

 Cower at <T near the surface. Sepals and petals crowning the (!') long, narrow, 

 incurved ovary, which, is half concealed in the spathe. Jl., Aug. (V. Amei> 

 icana MX.) 



