478 LEMNACK-E. (UUCKWEEI) FAMILY.) 



6. ACORUS, L. Sweet Flag. Calami-s. 



Spadix cylindrical, lateral, sessile, emerging from the side of a simple 2-edgC(3 

 scape which resembles the leaves, densely covered with perfect Howers. Sepals 

 6, concave. Stamens G : filaniciits linear • anthers kidney-shaped, 1-celled, 

 opening across. Uvary 2-.3-celled, with sevcr.il ])endnlous orthotropons ovules 

 in each cell: stigma minute. Frnit at length dry, gelatinous inside, 1- few- 

 seeded. Embryo in the axis of all)nmcn. — Pungent aromatic plants, especially 

 the thick creeping rootstocks {ailumus of the shops), which send up 2-edged 

 sword-like leaves, and scapes similar to them, bearing the spadix on one edge ; 

 the upper and more foliaceous prolongation sometimes considered as a kind of 

 open .-pathc. (The ancient name, from a privative, and Kuprj, the pupil of (he 

 eyf, having been used as a remedy for sore eyes.) 



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

 lowish-green) sjjadix. — Margin of rivulets, swamps, &c. Probably truly in- 

 digenous northward. June. (Eu.) 



Order 108. L,EilIl>f.4CE.13. (Duckweed Family.) 



Minute stemless plants, Jioalinr/ free on the icater, destitute of distinct stem 

 and foliage, being merely a frond, producing one or few monoecious flowers 

 from the edge or upper surface, and commonbj hanging roots from under- 

 ■neath : ovules rising from the base of the cell. Fruit a \- 7-seeded utricle. 

 Seed large; the apex or radicular extremitji of the seed-coat separable as 

 an operculum or lid (as in Cabomba, &c.) Embryo straight, surrounded by 

 Jieshy or sometimes very scanty albumen — The simplest, and some of them 

 the smallest of flowering plants, j)ropagating by the proliferous growth of a 

 new individual from a cleft in the edge or base of the parent frond, remain- 

 ing connected for some time or separating, also by autumnal fronds in the 

 form of minute bulblets, which sink to the bottom of the water, but rise 

 and vegetate in spring; the flowers (in summer) and fruit scarce, in some 

 species hardly ever seen. Frond more or less cavernous ; the upper sur- 

 fjice furnished with stomata. — These plants may be regarded as a sort of 

 very simpli6ed Aracea;. 



Arranged from notes contributed by C. F. Austin, Esq., who is pre- 

 paring a monograph of the American Lenmacete. 



1. LEMNA, L. DucivWEED. Duck's-meat. 



Flowers produced from a cleft in the margin of the frond, usually three to- 

 gether surrounded by a spathe ; two of them staminate, consisting of a stamen 

 only; the other ])istiliate, of a simple pistil; the whole therefore imitating a 

 single diandrous flower. Ster. Fl. Filament slender : anther 2-celled, didy- 

 mous ; the cells dehiscent transversely ; iiollcn-grains large, spherical, muricate. 

 Fert. FL Ovary 1-celled : style and truncate or funnel-shaped stigma simple. 

 Ovules and, seeds 1-7. — Fronds producing rootlets underneath, proliferous 



