436 MONOECIA TETRANDRIA. 



371. COMPTONIA. Sweet fern. 



C. asplenifolia. 



HAB. Woods. May. Shrub 2 3 feet high; aromatic; /ear. lobed- 

 pinnat. 



TETRANDRIA. 



372. ERIOCAULON. Pipewort. 



E. pellucidum : scape slender, about 7-furrowed ; leaves linear-subulate, 

 canaliculate, smooth, pellucid, 5-nerved, transversely striate ; head 

 small, globose ; scales of the involucrum oval, obtuse. 



HAB. Water. June, If.; scape 4 Gin. high; leaves rod., cesp.;Jl. 

 white. 



373. ALNUS. Alder. 



A. serrulata: leaves obovate, acuminate, with the veins of their axils 

 hairy underneath ; stipules elliptical, obtuse. 



HAB. Low grounds. March April. Shrub 8 15 feet high, much 

 branch. 



374. BOEHMERIA. 



B. cylindrica : leaves opposite, ovate-oblong, acuminate, dentate, smooth ; 

 flowers dioecious ; sterile spikes glomerate, interrupted ; fertile cylin- 

 drical ; stem herbaceous. 



HAB. Shady swamps. July Aug. Ij. ; stem slender, 2 feet high ; 

 leaves petiol. ; Jl. minute. 



375. URTICA. Nettle. 



U. pumila : leaves opposite, ovate, acuminate, 3-nerved, serrate, inferi- 

 or petioles as long as the leaves ; flowers monoecious, triandrous, in 

 corymbed heads, shorter than the petioles. 



HAB. Wet places. July Aug. ; stem succulent, semitranspa- 

 rent ; leaves shining. 



U. dioica: leaves opposite, cordate, ovate-lanceolate, coarsely serrate; 

 flowers dioecious ; spikes paniculate, clustered by pairs, longer than 

 the petiole. 



HAB. Road-sides, &c. May, 1\. ; stem 23 feet high, erect ; fl. 

 small, green ; plant stinging. . 



U. divaricata : leaves alternate, ovate, acuminate, rather smooth ; peti- 

 oles long, ciliate ; panicles axillary, solitary, much branched and di- 

 varicate, longer than the petiole ; stem stinging. 



HAB. Damp rocky places. July Aug. Tj. ; "stem 23 feet high, 

 branch. ; leaves not cordate. 



U. canadensis : loaves cordate-ovate, acuminate-serrate, hispid on both 

 sides ; panicles axillary, generally by pairs, much branched and di- 



