638 Order 116.— EMPETKACE^E. 



short petioles ; upper spikes long and sterile, lower short, dense, fertile. — Borders 

 of ponds. S. W. States. St. strict, 2 to 3f high, very rough. Lvs. 3 to 5' loDg, a 

 fourth as wide, thick, on petioles 4 to 7'' long. Fertile spikes as long as the pet- 

 ioles, sterile nearly as long as the leaves. 



5. PARIETA V RIA, Tourn. Pellitory. (Lat. 2>aries, a wall ; some 

 of the species prefer to grow on old walls.) Flowers moncecio-polyga- 

 mous, in clusters, surrounded by a many-braeted involucre. <3 Calyx 

 4-sepaled ; stamens 4, at first incurved, elastically expanding. $ Calyx 

 tubular-campanulate, 4-lobed, inclosing the ovary; stigma tufted ; ache- 

 nium polished, inclosed within the persistent calyx. — Herbs weed-like, 

 with usually alternate lvs. Clusters of green fis., axillary. 



1 P. Pennsylvanica Muhl. Lvs. oblong-lanceolate, veiny, tapering to an obtuse 

 point, entire, punctate with opaque dots; invol. longer than the flowers. — (J) A 

 rough, pubescent herb, found in damp, rocky places, Vt. to "Wis. and Ga. Stem 

 erect, simple or sparingly branched, 6 — 12' high. Leaves alternate, entire, hairy 

 and rough, about 1' wide and 3 or 4 times as long, petiolate, and ending with an 

 obtuse acumination. Segments of the involucro about 3, lance-linear. Flowers 

 dense, greenish and reddish white. May, June. 



2 P. Floridana Nutt. Lvs. roundish-ovate, obtuse, as long as the petiole, opaquely 

 punctate; fls. as long as the involucre. — (J) Damp, sandy soils, Ga. and Fla. St. 

 decumbent at base, branches erect, 10 to 12' high. Lvs. small, 1' long, including 

 the filiform petiole, 3 to 5" wide. Bracts linear. May — Oct. 



6. HU'WULUS, L. Hop. (Lat. humus, moist earth; the hop grows 

 only in rich soils.) Flowers $ $ . — & Calyx 5-sepaled ; stamens 5 ; 

 anthers with 2 pores at the summit. $ Bracts imbricate, large, entire, 

 concave, persistent, 1-flowered, forming an oblong ament; calyx of 1 

 sepal; membranous, entire, persistent; styles 2; achenium invested by tho 

 thin calyx; embryo coiled. — II Twining with the sun. Lvs. opposite. 

 Fls. in axillary panicles and strobile-like aments. 



H. lupulua L. The hop-vine is found wild in hedges, &c, throughout this country, 

 and is, as every one knows, extensively cultivated for the sake of its ameut-liko 

 fruit. It has a long, annual stem of rapid growth, always twining with the sun, 

 rough backwards with reflexed prickles. Leaves very rough, generally 3-lobed, 

 deeply cordate at base, on long stalks. Flowers of the barren plants innumer- 

 able, panicled, greenish ; those of the fertile, in aments with large scales. Cal. 

 and scales in fruit covered with reddish, resinous atoms (lupulin) in which the 

 virtue resides. Jl. 



7. CAN'NABIS, Tourn. Hemp. Flowers S $ .— $ Calyx 5-parted ; 

 stamens 5. $ Calyx entire, oblong-acuminate, opening longitudinally 

 at the side ; styles 2 ; caryopsis 2-valved, inclosed within the persistent 

 calyx ; embryo curved. Lvs. opposite, digitate. Fls. axillary, $ in 

 cymous panicles, ? in sessile spikes. 



C. sativa L. Lvs. palmately 5 to 7-foliate. — The hemp springs up spontaneously 

 in our hedges and waste grounds. It is a tall, erect plant, with handsome petio- 

 late leaves. Llls. lanceolate, serrate, 3 to 5' long, % as wide, tho middle one 

 largest. Fls. small, green, solitary and axillary in the barren plants, spiked in 

 the fertile ones. It is cultivated iu Ky., Tenn., &c, as one of tho staples. Jn. 

 § India. 



Order CXVI. EMPETRACRJL Crowberries. 



Shrubs low, evergreen, heathlikc, with crowded, narrow leaves and small, diclin- 

 ous flowers. Calyx of 4 to C, hypogynous, persistent, imbricated scales, the inner 

 often colored. Stamens 2 or 3, pellen grains quaternate. Ovary free, 2 to 9-cellod, 



