CANNABIS CXXX. URTICACE^E. 511 



ing in shades, smooth and shining. Leaves on long petioles, especially the 

 lower ones, smoothish, about 2' long and f as wide. Flowers in short heads 

 or corymbs, axillary. A species without stings. Aug., Sept. 



5. U. URENS. Burning or Dwarf Nettle. 



Lvs. broadly elliptic, about 5-veined, acutely serrate ; clusters glomerate, 

 by pairs. Weed, in cultivated grounds. Stem 12 20' high, hispid with 

 venomous stings, branching. Leaves 1 2' long, f as broad, on short petioles 

 and with large serratures. Stipules small, lanceolate, reflexed. Flowers in 

 creeping, pedunculate clusters about as long as the petioles, both the sterile and 

 tertile in the same axil. Rare. June, July. $ 



6. S. GRACILIS. Ait. Slender Nettle. 



St. erect, strict, sparingly hispid ; Ivs. ovate-lanceolate, subacuminate, 

 coarsely and somewhat doubly serrate, 3-veined, smoothish above, hispid be- 

 neath on the veins ; spikes elongated, pinnately branched, a little shorter than 

 the leaves ; As. glomerate. 7J. Northern and Western States, and Brit. Am. 

 Stem 2 3f high. Flowers minute, green. July, Aug. 



6. BCEHMERIA. Willd. 



Named for G. F. Boehmer, a German botanist 



Flowers c? or c? 9. cf Calyx 4-parted, with lanceolate, acute seg- 

 ments; stamens 4. 9 achlamydeous ; ovary and style 1, in the axil 

 of a bract ; achenium compressed, margined. Herbs or shrubs, nearly 

 allied to Urtica. Lvs. opposite or alternate. Fls. clustered. 



B. CYLINDRICA. (Urtica cylindrica and capitata. Linn.} False Nettle. 

 Herbaceous ; Ivs. opposite, ovate-lanceolate, acuminate, dentate, smooth ; 

 fl s - c? 9 5 sterile spikes glomerate, interrupted, fertile cylindric. A coarse, nettle- 

 like plant, in swamps and bottoms, Mid. and Western States ! Stem slender, 

 obtusely 4-angled, channeled on each side, 2 3f high. Leaves 3-veined, 3 5' 

 long, J as wide, on long petioles. Flowers minute, the fertile ones in axillary, 

 cylindric spikes, 1 2' in length, the barren spikes rather longer and more 

 slender. July, Aug. . 



Spite' shorter, subcapitate ; petioles somewhat shorter. 



y. ^B. iateriflora. Muhl.} Lvs. roughish; spi&es longer and much interrupted. 



7. PARIETARIA. 



Lat. paries, a wall ; some of the species prefer to grow on old walls, &c. 



Flowers monoecious-polygamous, in clusters surrounded by a many- 

 cleft involucre ; calyx 4-parted ; stamens 4, at first incurved, then 

 expanding with an elastic force ; ovary and style 1 ; achenium pol- 

 ished, enclosed within the persistent calyx. Herbs with usually al- 

 ternate haves. Clusters of green Jlowers axillary. 



P. PENNSYLVANIA. Pellitory. 



Lvs. oblong-lanceolate, veiny, tapering to an obtuse point, punctate with 

 opaque dots; invol. longer than the flowers. A rough, pubescent herb, found 



I 



acumination. Segments of the involucre about 3, lance-linear. Flowers dense, 

 greenish and reddish-white. Rare. June. 



SECTION 3. CANXABINEJE. 



Herbs, erect or twining, with a watery juice, c? racemose or panicu 



late, 9 in a cone-like ament. Albumen 0. 



8. CANNABIS. 



Arabic ganeb, hemp. 



Flowers cT 9- $ Calyx 5-parted. 9 Calyx entire, oblong-acumi 

 nate, opening longitudinally at the side ; sty. 2 ; ach. ? 2-valved, en 



