314 URTICACEiE. 



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

 rather acute, narrowed 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. Penn. May, June. %. — Stem 2 — 3 feet high, simple or with 

 a 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- wedge form, 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. oblusata 

 Pursh. 



Sandy fields. N. Y. to Car. July— Sept. (J). — Stem 8—18 inches high, um- 

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

 Sterile flowers rather numerous. Wartwort 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. 



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

 Champlain. Odkes. Can. Hook. ®. — Stem about a foot high. Leaves mem- 

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



Broad-leaved Spurge. 



Order CXI. URTICACE^.— 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. Z/iwi.— Nettle. 

 (From the Latin nro, to hum ; 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 elUptic or roundish-ovate, somewhat 5-herved, 

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

 the leaves. 



