LEMNACE^E. (DUCKWEED FAMILY.) 551 



and a cluster of very large ami broad entire veiny leaves, preceded in earliest 

 spring by the nearly sessile spathes, which barely rise out of the ground. 

 (Name from <rv/j.n\oKri, i-ininc<-tioii, aud nap-nos, fruit, in allusion to the coales- 

 cence of the ovaries into a compound fruit.) 



1 . S. fcetldus, Salisb. Leaves ovate, cordate, becoming 1 - 2 long, short- 

 petioled ; spathe spotted and striped with purple and yellowish-green, ovate, 

 incurved ; fruit (in autumn) 2-3' in diam., in decay shedding the bulhlet-like 

 seeds, which are 4-6" long. Bogs and moist grounds, N. Scotia to N. C., 

 west to Minn, and Iowa. 



5. ORONTIUM, L. GOLDEN-CLUB. 



Spathe incomplete and distant, merely a leaf-sheath investing the lower part 

 of the slender scape, and bearing a small and imperfect bract-like blade. 

 Flowers crowded all over the narrow spadix, perfect ; the lower with 6 con- 

 cave sepals aud 6 stamens ; the upper ones with 4. Filaments flattened ; an- 

 thers 2-celled, opening obliquely lengthwise. Ovary 1 celled, with an anatropous 

 ovule ; stigma sessile, entire. Fruit a green utricle. Seed without albumen. 

 Embryo thick and fleshy, " with a large concealed cavity at the summit, the 

 plumule curved in a groove on the outside." (Torr.) An aquatic perennial, 

 with a deep rootstock, long-petioled and entire oblong and nerved floating 

 leaves, and the spadix terminating the elongated scape ; its rather club-shaped 

 emersed apex as thick as the spadix. (Origin of the name obscure.) 



1. O. aquaticum, L. Ponds, Mass, to Fla. May. 



6. AGO HITS, L. SWEET FLAG. CALAMUS. 



Spadix cylindrical, lateral, sessile, emerging from the side of a simple 2-edged 

 scape which resembles the leaves, densely covered with perfect flowers. Se- 

 pals 6, concave. Stamens 6 ; filaments linear ; anthers kidney-shaped, 1-cellecl, 

 opening across. Ovary 2 - 3-celled, with several pendulous orthotropous ovules 

 in each cell ; stigma minute. Fruit at length dry, gelatinous inside, 1 - few- 

 seeded. Embryo in the axis of albumen. Pungent aromatic plants, espe- 

 ciallv the thick creeping rootstocks (calamus of the shops), which send up 2- 

 edged sword-like leaves, and scapes somewhat like them, bearing the spadix on 

 one edge ; the upper and more foliaceous prolongation sometimes considered as 

 a kind of open spathe. ("Ax-upas, the ancient name, of no known meaning.) 



1. A. Calamus, L. Scape leaf-like and prolonged far beyond the (yel- 

 lowish-green) spadix. Margins of rivulets, swamps, etc., N. Scotia to Fla., 

 west to Minn., Iowa, and E. Kan. 



ORDER 124. LEMNACE^. (DUCKWEED FAMILY.) 



Minute stemless plants, floating free on the water, destitute of distinct 

 stem and foliage, being merely a frond, producing one or few moncecious 

 ftoivers from the edge or upper surface, and commonly hanging roots from 

 underneath; ovules rising from the base of the cell. Fruit a 1 7-seeded 

 utricle. Seed large ; the apex or radicular extremity of the seed-coat sepa- 

 rable as an operculum or lid (as in Cabomba, etc.). Embryo straight, sur- 

 rounded by fleshy or sometimes very scanty albumen. The simplest, and 



