URTICACEiE. 354 URTICA. 



Consjicctus of the Genera. 



fFls. spicate or ( Feilile calyx 2-sepaled. Vrtica. 1 



f Lvs. simple. < paniculate. | Fertile calvx 0. . . B/zlimeria. 5 



j Stamens 4. ( Flowers capitate, involucrate. . . Pan'etaria. 2 



( erect. ( Leaves palmalely 5— 7-foliate. Stameii.s 5. . . . Cannabis, 'i 



Herbs ...( climbin<r. Diwcious. Stamens 5. Fertile flowers in aments. Humulits. 4 



Trees and ] Flowers in cylindric spikes, not enclosed Morus. 6 



shrubs ... I Flowers clustered together within a fleshy receptacle. . Ficus (omitted). 



1. U'RTICA. 



Flowers moncecious, sometimes dicecious. Slerile. — Calyx 

 4-sepaled, with a cup-shaped, central rudiment of an ovary ; 

 stamens 4. Fertile. — Calyx 2-leaved, persistent, at length 

 surrounding the shining, compressed achenium; style 1. 



Lat. uro, to burn ; in reference to the stinging species. Herbs, often with 

 stinging hairs. Juice watery. Lvs. accompanied with stipules. Fls. clus- 

 tered, a.xillary, green. 



* Leaves alternate. 



1. U. CaNADE'NSIS. U. Canadensis and divaricata. L. 

 Hispid and stinging; leaves ovnln, ncmmn-dle, serrate; panicles ax\\]a.Ty, 



divaricate-branching, shorter than the jjeliolps. In damp places. Stem 2 — 6 

 feet high. Leaves broadly ovate, '.^ — 5 inches long, regularly toothed, often 

 with a small sinus at base, more or less hispid both sides, often nearly smooth. 

 Lower petioles 3 inches long. Flowers minute, in axillary panicles which 

 vary from 1 to 3 or 4 inches in lengtli, the lower ones generally barren. July, 

 Aug. For. On account of its tough fibres it has been proposed as a substi- 

 tute for hemp. Jlevip j\ettle. 

 p. stem 2 — 3 feet high; panicles shorter than the lower petioles. 

 * * Leaves opposite. 



2. U. DIOl'CA. 



Hispid and stinging ; leaves cordate, coarsely serrate ; flniccrs dioscious; 

 xpiUcs much branched, in pairs. Grows by roadsides, A:c. Stem 2 — 4 feet 

 high, branching, obtusely 4-angled, with opposite short-stalked leaves which 

 are 3 — 4 inches long and about ;^ as wide. 'Flowers small, green, in a.xillary 

 clusters, of mean aspect, corresponding with the insidious character of the 

 plant. " Its power of stinging resides in minute, tubular hairs or prickles 

 which transmit a venomous fluid when pressed.'' Bigelow. July, Aug. 

 Per. Common jYettCs. 



3. U. pu'mila. 



Glabrous ; leaves ovate, acuminate, 3-nerved, serrate ; loircr peliahs as long 

 ns the leaf: flowers monoecious, triandrous, in corynibed heads shorter than 

 the petioles. In waste places, about buddings, &c. Stem fleshy, semi- 

 transparent when growing in shades, smoolii and shining. Leaves on long 

 petioles, especially the lower ones, smoothish, about 2 inches long and § as 

 wide. Flowers in short heads or corymbs, axillary. A species without stings. 

 Aug. Sept. Per. Riclmetd. 



4. U. URENS. 



Leaves broadly elliptic, about 5-nervcd, acutely serrate; clusters ^^omemie, 

 by pairs. An annual weed, in cultivated grottnds. Stem 12 — 20 inches 

 high, hispid vi'ith venornotis stings, branching. Leaves 1 — 2 inches long, |as 

 broad, on short iictioles and with largo serr-itures. Sti])ules small, lanceolate, 

 lefiexed. Flowers in drooping, pedunculate clusters about as long as the 

 petioles, both the sterile and fertile in the same axil. Rare. Introduced. 

 June, July. Ann. Burning J\"ctde. 



