Jumpenis.'\ DIOECIA MONADELPUIA. 377 



4. P. nigra, L. (black Poplar^; leaves deltoid acute serrated 

 glabrous on both sides, fertile catkins cylindrical lax, " stigmas 

 4." E.Bot. t. 1910. 



Watery places and river- banks. Scarcely indigenous to Scotland. 

 Fl. Apr. Tj . — A very large tree of cpiick growtli, producing a light, not 

 valuable wood; as is the case with most trees that come soon to per- 

 fection. 



10. Rhodiola. Linn. Rose-root. 



1. R. rosea, L. (Rose-root). E. Bot. t. 508. 



Wet rocks, on the high mountains of the north of England and Ire- 

 and and in the nortli-west of Scotland, abundant ; likewise on cliffs by 

 the sea-shore. Fl. June. If. — Root large, woody, when dry yielding a 

 smell that has been compared to that of Eases. Stem 6 — 8 or 10 inches 

 high, simple. Leaves numerous, obovato-oblong, serrated at the point, 

 and in the sterile plant often tipped witli a reddish tinge. Flowers in 

 a small, compact, terminal ci/me, yellow ; agreeing wiili Sedum in every 

 thing but the number of their parts, and having the habit of 5. Telepliium. 



DIOECIA— ENNEANDRI A. 



11. Mercurialis. Linn. Mercury. 

 X.M.perennis, L. {perennial or Dog's Mercury); stem perfectly 



simple, leaves rough, x-oot creeping perennial. E. Bot. t. 1872. 



Woods and shady places, abundant. Fl. Apr. May. If. — About 1 foot 

 high. Leaves mostly on the upper part of the stem, ovate, serrated. 

 Flowers in axillary, short, lax spikes. The plant in drying often becomes 

 of a bluish, or blackish green. 



2. INI. annua, L. {annual Mercury); stem with opposite branch- 

 es, leaves glabrous, root fibrous annual. E. Bot. t. 559. — ^. M. 

 amhigua, L.fil. — Bab. in E. Bot. Svppl.ined.Prim. Fl. Sam. ined. 



Waste places about towns and villages, not common. Fl. Aug. 0. 

 — 1 ft. high. Sterile flowers in long^ interrupted axillary spikes.— 9>. 

 Jersey. Babington and Christy. (1807). 



12. Hydrocharis. Linn. Frog-bit. 



1. H. Morsus Kdnce, L. {common Frog-bit). E. Bot. t. 808. 



Ditches and ponds in England and Ireland. Scarcely found in Scot- 

 land. Fl. July. If. — Floating, and sending down long radicles from the 

 horizontal sterns. Leaves petioled, reniform, entire. Flowers subum- 

 bellate, large, white, delicate, arising from pellucid membranous spathas. 



DIOECIA— MONADELPHIA. 



13. JuNiPERUS. Linn. Juniper. 



1 . J. communis, L. (common Juniper) ; leaves 3 in a whorl 

 linear mucronate spreading or imbricated longer than the berry. 

 E. Bot. t. 1100.-/3. nana, small, procumbent, leaves broader. 

 J. nana, Willd.~E. Bot. Suppl. t. 2743. 



Woods and heaths, frequent.— /S. abundant in the mountains of Wales, 

 Scotland, and Ireland, and on low ground in the northern parts. FL 

 Mav. T? .— A shrub, extremely variable in size, bearing numerous, linear, 



