DESCRIPTION OF MEDICINAL PLANTS. 
95 
ing nearly the generic characters of the foregoing, but spike- 
lets 4-8 flowered, placed flatwise on the rhachis. Spikelets 
compressed, 2-ranked, alternate on opposite sides of a solitary, 
terminal spike, simple at each joint, glabrous or nearly so ; 
glumes 3-7-nerved, rhachis glabrous, but rough on the edges > 
awns, when present, straight ; leaves flat and often roughish or 
pubescent above. It exists in several varieties ; the one which 
appears as an obnoxious intruder into our fields and gardens, 
on account of its very long, creeping and matted rootstocks, 
is a naturalized immigrant from Europe; while another, 
known in the Western States as Blue-joint, or Blue-stem, is 
indigenous and highly esteemed there as a nutritious and 
productive meadow-grass. It is used as an emollient. 
Zea Mays, L. Indian Corn. The styles and stigmas known 
as corn silk, collected before drying up. It is received into 
the latest edition of the U. S. Dispensatory in the list of the 
there called u official” drugs. It is exhibited in the form of 
a fluid extract as a mild diuretic. 
Class III.— CRYPTOGAMOUS ACROGENS. 
FILICES. (Ferns) 
Polypodinm vulgare, L. Polypody. Leafy plant, with the 
leaves (fronds) raised on a petiole (stipe), rising from a 
creeping root, rolled up in the bud and bearing on the 
under surface small, reticulated sporangia, in rounded fruit- 
dots (sori) midway between the midrib and the margin. 
Fronds evergreen, oblong, smooth both sides, 4-10' high, 
simple and deeply pinnatifid ; the divisions linear-oblong, 
obtuse or somewhat acute, remotely and obscurely toothed. 
Veins once or twice forked. Fruit-dots large. Common 
on rocks and trees in the Cumberland and Alleghany Mount- 
ains. The leaves are used. (Parke, Davis & Co.) 
Adiantum pedatum, L. Maiden-hair. A delicate and elegant 
fern, having the frond forked at the summit of the upright, 
slender stalk, 9-15' high, the recurved branches bearing on 
one side several slender-spreading pinnate divisions ; pin- 
