449 
ARACEjE. (arum family.) 
shaped, 1-celled, 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, especially the thick 
creeping rootstocks ( calamus 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 some¬ 
times considered as an open spathe. (The ancient name, from a 
privative, and Koprj , the pupil of the eye , having been used as a 
remedy for sore eyes.) 
1- A. Calamus, L. Scape prolonged and leaf-like far be¬ 
yond the cylindrical (yellowish-green) spadix. — Margin of rivulets, 
swamps, and wet meadows ; probably introduced from Europe. June. 
Order 110. EEMJYACEAE. (Duckweed Family.) 
Minute stemless plants , floating free on the water , desti¬ 
tute of distinct stem and foliage , but a flat frond , produc¬ 
ing one or two monoecious flowers from a chink at the edge 
or upper surface , and usually hanging roots from under¬ 
neath. — Fructification much as in the Arum Family, of 
which these plants are minute and greatly reduced forms. 
1 * LEMNA, L. Duckweed. Duck’s-meat. 
Flowers appearing from a cleft in the edge of the frond, three 
together bursting through a thin and membranous urn-shaped 
spathe; two of them consisting of single stamens (one develop¬ 
ed rather earlier than the other), with thread-like filaments and 2- 
celled anthers; the other a 1-celled ovary forming a utricle in 
fruit: stigma funnel-form, ovules erect. Embryo in the axis of 
fleshy albumen. — Roots with a sheath-like appendage on the end. 
Fronds laterally proliferous by a sort of budding, and producing 
little bulblets which sink to the bottom of the water in autumn but 
rise to develop on the surface in spring. Flowers seldom found. 
(An old Greek name, of uncertain meaning.) 
* Fronds bearing single roots from the lower surface. 
1- E. perpusllla, Torr. Fronds obovate, thin (l"-lj|" long), 
single or grouped ; ovule solitary , anatropous; seed erect , striate. — 
Staten Island, New York, Torrey. August. 
38* 
