€70 Ow>EB 132. — LEMNACB^E. 



6. ORON'TIUM, L. Golden Club. (Name of doubtful origin.) 

 Spathc none ; spadix cylindric, covered with perfect flowers ; perianth 

 4 to 6-sepaled ; stamens 4 to 6 ; ovary few ; stigma sessile ; fruit a dry- 

 berry or utricle, seed without albumen. — Zf Acaulescent, aquatic. Fls. 

 yellow at the summit of the scape, which thickens upwards into the 

 spadix. 



O. aquaticum. — This interesting plant is a native of inundated banks and pools, 

 U. S. Lvs. lanceolate, 6 to 9' by 2 to 3', smooth, of a deep green, velvet-liko 

 surf ice above, paler beneath, on long, radical petioles. Scapo thick and terete, 

 about a foot in length, closely invested b}' a short sheath at base, and ending in 

 a spadix of a rich yellow color, covered with small perfect, yellow lis. of an 

 offensive odor — tho upper ones often tetramerous. May. 



7. ACiTRUS, L. Sweet Flag. (Gr. c, privative, and iwprj, the 

 pupil of tbc eye ; supposed to cure maladies of the eye.) Spadix cylin- 

 dric, covered with flowers, and issuing from the side of a leaf-like scape ; 

 perianth 0-sepaled ; stamens G, linear ; ovary free ; stigma sessile, min- 

 ute ; fruit dry, 3-celled, many-seeded. — If. Herbs with a fleshy, aroma- 

 tic rhizome. Lvs. radical, ensiform, as well as the scape. 



A. calamus L. Summit of the scape above the spadix very long and leaf-like. — 

 Grows in wet soils throughout the U. States. The thick, prostrate, creeping 

 rhizome is highly valued for its aromatic flavor, its warm and pungent taste. Tho 

 long, sword-shaped leaves are readily distinguished by the ridge running their 

 whole length. The cylindrical spadix is about 3' long and 3" diam., covered 

 with small, green flowers. Jn., JL 



Order CXXXII. LEMNACE^E. Duckmeats. 



Herbs minute, stemless, floating free upon tho water, and consisting of a leaf-like 



frond, or a tufc of leaves, with one or more fibrous roots. Flowers bursting from 



the substance of tho frond, or axillary, inclosed in a spathe, tiie sterile consisting of 



1 or 2 stamens, the fertile of a 1-celled ovary. Fruit a utricle, with 1 or more seeds. 



Embryo straight, in fleshy albumen. Fig. C02. 



Centra 4, xpeciex 20, little aquatics, widely diffused. They are regarded as reduced arc-Ids, 

 and among the simplest of Phenogamous plants. 



1. LEM'NA, L. Duck-meat. (Perhaps altered from XL\i\ia, a 

 .■scale.) Sterile and fertile flowers in the same spathe, the former 2 col- 

 lateral stamens, the latter a simple, carinate ovary, with a style and 

 stigma. — (J) Ilerbs, consisting of a frond (stem and leaf confounded), 

 sending down from the under surface roots which hang loosely in tho 

 water, and producing from the margins the spathaceous flowers. (The 

 following sections arc regarded as genera by Schleiden.) 



| LEMNA, Schleidcn. Fils. filiform. Ovule solitary. Frond with a single root. . ..Nos. 1 — 3 

 S TELMATOPHACE, Schl. Fils. dilated in the middle. Ovs. 2 to 7. Fronds l-rooted..No. 4 

 $ SPIItODELA, Schl. Fils. narrowed below. Ovules 2. Frond many-rooted No. 5 



1 L. trisulca L. Ivy-leaved Duck-meat. Fronds elliptic-lanceolate, thin, eer- 

 rate at one extremity and caudate at the other ; roots solitary. — Floating in ponds 

 and pools of clear water. Fronds nearly £' in length, diaphanous, with a tail-like 

 appendago at base, obtuse at apex, the new ones issuing in a cruciate manner 

 from lateral fissures in the margin of the old. Root a solitary fiber, ending in a 

 eheath. Flowers very minute. Utricle sitting on the upper surface of the frond. 

 June — Sept. 



2 L. minor L. Fronds thickish, roundish or obovate, several conjoined ; root soli- 

 tary. — This little floating plant occurs in dense patches on the surface of stagnant 

 waters. The leaves, properly fronds, adhere 2 — 3 together, 2" in length, rather 



