412 URTICACEuE. (nettle FAMILY.) 



with a single erect orthotropous ovule. Stigma simple or tufted. Ache- 

 nium commonly enclosed in the dry persistent calyx. Embryo straight, 

 in the axis of fleshy albumen. 



Synopsis. 



* Plants armed with stinging hairs. 



1. tJRTICA. Stamens 4. Stigma tufted. Achenium straight. 



2. LAPOKTEA. Stamens 5. Stigma subulate. Achenium oblique. 



* * Plants destitute of stinging hairs, 

 t- Flowers in cymose clusters. 

 8. PILEA. Clusters naked. Calyx-lobes unequal. Leaves opposite. 



4. PARIETARIA. Clusters involucrate. Calyx-lobes equal. Leaves alternate. 



^- -I- Flowers in spiked clusters. 



5. BCEHMERIA. Stigmas subulate, leaves opposite or alternate. 



1. URTICA, Toum. Nettle. 



Flowers monoecious or dioecious. Calyx of the sterile flower 4-parted. Sta- 

 mens 4, inserted around the abortive ovary. Calyx of the fertile flower 4-sepa- 

 lous, unequal ; the inner ones dilated in fruit, and enclosing the achenium. 

 Stigma sessile, tufted. Achenium straight, ovate, smooth, compressed. — Herbs, 

 with stinging hairs, opposite leaves, and greenish flowers, in panicled spikes or 



close clusters. 



* Flowers in panicled or simple spikes. 



1. TJ. gracilis, Ait. Stem tall, 4-angled, smoothish, slender ; leaves long- 

 petioled, ovate-lanceohxte, coarsely serrate, acute, rounded at tiie base, 3-5- 

 nerved, smoothish, the petioles bristly ; spikes very slender, loosely panicled. 

 (U. procera, Willd.) — Low ground in the upper districts, and northward. July 

 and Aug. Ij. — Stem 3° - 4° high, mostly simple. Leaves thin, 4'-6' long. 



2. U. dioiea, L. Hispid throughout ; stem 4-angled, pubescent above, 

 branching ; leaves rather short-petioled, ovate, cordate, acuminate, coarsely ser- 

 rate, pubescent beneath ; spikes much branched ; flowers often dioecious. — 

 "Waste places. In Carolina, PwrsA. Introduced. June -Aug. H. — Stem 2°- 

 3° high. Leaves 3' - 4' long, thicker than in No. 1, and flowers larger. 



3. IT. capitata, Willd. Stem 4-angled, roughish ; leaves large, long- 



petioled, rough, oblong-ovate, slightly cordate, coarsely serrate, 3-nerved ; those 



on the branches alternate ; spike solitary, leafy at the summit. — Wet shaded 



places, North and South Carolina, Curtis, Elliott. July and Aug. — Stem 3°- 



50 high. 



* * Flowers in simple clusters shorter than the petioles. 



4. TJ. urens, L. Stem 4-angled, hairy ; leaves ovate, coarsely serrate, 

 5-nerved, hairy ; clusters by pairs in each axil, loose, pedunclcd. — Damp soiL 

 Introduced. Dec. -Feb. Q — Stem 1° high. 



5. IT. Chamaedryoides, Pursh. Stem smooth ; leaves small, nearly ses- 

 sile, ovate, coarsely serrate, hairy beneath, hairy and bristly above; clusters 

 nearly sessile, globose, dense ; calyx hairy. — St. Simon's Island, Georgia, 

 Elliott. Feb. and March. — Stem 4' - 6' high. 



