314 URTICACE^E. 



11. E. memoralis Darlingt. : stem erect; leaves alternate, lance-oblong, 

 rather acute, harrowed at the base, subsessile, entire, hairy beneath ; um- 

 bel 5 8-cleft, the rays 1 2-forked; petaloid segments of the involucre 

 dilated, subreniform. E. pilosa Pursh not of Linn. 



Moist woods. Perm. May, June. 'ij.. Stem "2 3 feet high, simple or with 

 u slender peduncle-like branch from the axils of the leaves. Flowers in a ter- 

 minal umbel and on slender axillary branches. Wood Spurge. 



12. E. helioscopia Linn. : smooth : stem erect, branched above ; leaves 

 alternate, broadly obovate-wedgeform, obtuse, serrulate, the bracteal ones 

 broader ; umbel 3 5-cleft, the rays 2 3-times forked ; involucre oblong- 

 turbinate, terminal and in the forks of the umbel, nearly sessile. E. obtusata 

 Pursh. 



Sandy fields. N. Y. to Car. July Sept. .- Stem 818 inches high, um- 

 bellately branched at the top. Leaves membranaceous. sometimes retuse. 

 Sterile flowers rather numerous. Wartuxrrt Spurge. 



13. E. platyphylla Linn. : stem erect, smooth ; leaves elliptic or oblan- 

 ceolate, mostly acute, finely serrulate, hairy beneath ; floral ones cordate ; 

 umbel 3 5-cleft; the rays 2 3-times forked ; glands of the involucre oval ; 

 capsule warted. 



ISear Portland Harbor, Lake Erie. Dr. Kneishern. On the islands of Lake 

 Champlain. Oakes. Can. Hook. (T). Stem about a foot high. Leaves mem- 

 branaceous, tapering to the base, sessile. Glands large. Introduced ? 



Broad-leaved Spurge. 



ORDER CXI. URTICACE^E. NETTLES. 



Flowers monoecious or dioecious, scattered or clustered. Per- 

 ianth membranous, lobed, persistent. Stamens definite, distinct, 

 inserted into the base of the calyx and opposite its lobes. 

 Ovary superior, simple ; stigma simple. Fruit a simple inde- 

 hiscent nut, surrounded either by the membranous or fleshy 

 perianth. Embryo straight, with fleshy albumen. Trees, 

 shrubs or herbs. Leaves alternate, often covered with pungent 

 hairs. Flowers inconspicuous. 



1. URTICA. Linn. Nettle. 



(From the Latin uro, to burn ; in allusion to its stinging property.) 

 Monoecious, rarely dioecious. STERILE FL. Perianth single, 

 of 4 roundish-obtuse leaves, containing the cup-shaped rudiment 

 of a germ. Stamens 4. FERTILE FL. Perianth mostly of 2 

 persistent leaves. Stigma 1. Nut orbicular-ovate, compressed, 

 shining. 



* Leaves opposite. 



1. U. urens Linn. : leaves elliptic or roundish-ovate, somewhat 5-nerved, 

 acutely serrate ; flowers in simple axillary clusters, which are shorter than 

 the Jeaves, 



