446 URTICACVLE. (NETTLE FAMILY.) 



9. PARIETARIA, Tourn. Pellitoky. 



Flowers monceciously polygamous ; the staminate, pistillate, and perfect in- 

 termixed in the same involucrate-bracted cymose axillary clustei-s ; the sterile 

 much as in the last ; the fertile with a tubular or bell-shaped 4-lobed and nerved 

 calyx, enclosing the ovary and the ovoid achenium. Style slender or none : 

 stigma pencil-tufted. — Homely, diffuse or tufted herbs, not stinging, with alter- 

 nate entire 3-ribbed leaves, and no stipules. (The ancient Latin name, because 

 growing on old walls.) 



1. P. Pennsylvaniea, Muhl. Low, annual, simple or sparingly branched, 

 minutely downy ; leaves oblong-lanceolate, thin, veiny, roughish with opaque 

 dots ; flowers shorter than the leaves of the involucre ; stigma sessile. — Shaded 

 rocky banks, Vermont to Wisconsin and southward. June - Aug. 



10. CANNABIS, Tourn. Hemp. 



Flowers dioecious ; the sterile in axillary compound racemes or panicles, with 

 5 sepals and 5 drooping stamens. Fertile flowers spiked-clustered, 1-bracted : 

 the calyx of a single sepal enlarging at the base and folded round the ovary. 

 Embryo simply curved. — A tall roughish annual, with digitate leaves of 5-7 

 linear-lanceolate coarsely toothed leaflets, the upper alternate ; the inner bark 

 of very tough fibres. (The ancient name, of obscure etymology.) 



1. C. sativa, L. (Hemp.) — Waste and cultivated ground. (Adv. from 

 Eu.) 



11. HUMULUS, L. Hop. 



Flowers dioecious; the sterile in loose axillary panicles, with 5 sepals and 5 

 erect stamens. Fertile flowers in short axillary and solitary spikes or catkins : 

 bracts foliaceous, imbricated, each 2-flowered, in fruit forming a sort of mem- 

 branaceous strobile. Calyx of a single sepal, embracing the ovary. Achenia 

 invested with the enlarged scale-like calyx. Embryo coiled in a flat spiral. — 

 Twining rough perennials, with stems almost prickly downwards, mostly oppo- 

 site heart-shaped and palmately 3 - 7-lobed leaves, with persistent ovate stipules 

 between the petioles. (Name thought to be a diminutive of humus, moist earth, 

 from the alluvial soil where the Hop spontaneously grows.) 



I. H. Lupulus, L. (Common Hop.) Leaves mostly 3-5-lobed, and 

 commonly longer than the petioles ; bracts, &c, smoothish ; the fruiting calyx, 

 achenium, &c, sprinkled with yellow resinous grains, giving the bitterness and 

 aroma of the hop. — Alluvial banks : common northward and westward, where 

 it is clearly indigenous, July. (Eu.) 



Order 100. PLATANACEJE. (Plane-tree Family.) 



Trees, with watery juice, alternate palmately-lobed leaves, sheathing stip- 

 ules, and monoecious flowers in separate and naked spherical heads, destitute 

 of calyx or corolla ; the fruit merely club-shaped, 1-seeded nutlets, furnished 

 with bristly down along the base : consists only of the following genus (of 

 uncertain relationship). 



