LXXI, URTICACEA. 399 
and small, herbaceous, unisexual flowers. Perianth in the 
males regular and simple. Stamens as many as segments of 
the perianth and opposite to them, or rarely fewer. Perianth 
of the females often less divided. Ovary free or rarely adhe- 
rent to the perianth, with a single ovule, and 1 or 2 styles or 
stigmas. Fruit small, 1-seeded, dry or rarely succulent. Seed 
with or without albumen, the radicle pointing upwards. 
A very large Order, chiefly tropical, of which the few British species 
give a very inadequate idea. It is readily distinguished from Huphorbiacee 
by the single-seeded fruit, from Amentacee by the regular perianth of the 
male flowers. 
Erect herbs. Leaves opposite . ‘ 5 ‘ ; : : . Le Urerrex: 
Erect or procumbent herb. Leaves alternate . : : - . 2. PARIETARIA. 
Talltwiner. Leaves opposite . “ . - ; ; F . & HUMULUS. 
Among exotic genera in cultivation may be mentioned the Hemp (Can- 
nabis), which, although an erect herb, is in many respects allied to the 
Hop; the Fig (Ficus), in which the flowers are collected in great numbers 
withinside a succulent receptacle, popularly called the fruit; and the Mul- 
berry (Morus), in which the flowers are collected in heads on the outside 
of a receptacle, and become succulent as the fruit ripens. 
I. URTICA. NETTLE. 
Erect herbs, with stinging hairs and opposite leaves. Flowers in axil- 
large clusters or spikes; the males with a perianth of 4 segments and 4 
stamens; the females with a perianth of 2 segments, or, if 4, the 2 inner 
ones larger. Fruit a flattened seed-like nut, enclosed in the perianth. — 
Stigma single, sessile, and tufted. 
A considerable genus, generally distributed over the globe. 
Annual and monecious. Flowers in nearly sessile short clusters 1. U. urens. 
Annual and monecious. Male flowers in loose spikes. Females 
in stalked, globular heads . . A : A : 5 . 2 Uzi pilulifera. 
Perennial, usually dicecious. Flowers in branched spikes . . 3. JU, dioica. 
1, U.urens, Linn. (fig. 901). Small Nettle.—An erect, branching 
annual, seldom above a foot high and often only a few inches, glabrous with 
the exception of the stiff, stinging hairs. Leaves ovate or elliptical, deeply 
and regularly toothed, more tender than in the two other species. Flowers 
- male and female intermixed, in small, loose, almost sessile axillary clusters. 
In cultivated and waste places, especially in rich soils, throughout 
Europe and temperate Asia, and carried out as weed of cultivation to other 
parts of the world. Common in Britain. #7. the whole season. 
2. U- pilulifera, Linn. (fig. 902). Roman Nettle-—An annual like 
the last, but coarser and taller, attaining 2 feet, and very stinging. Leaves 
ovate or heart-shaped, deeply and regularly toothed. Male flowers-in little, 
distinct clusters, along peduncles often as long as the leaves; the females 
in globular heads, on the summit of a peduncle from + to 1 inch long. 
When in fruit these heads are 4 or 5 lines in diameter, and thickly beset 
with stinging bristles. | 
' On roadsides, and in waste places, in ‘southern Europe. Further 
north only as an introduced weed in the neighbourhood of habitations, and 
