6 oo 
URTICA 
Urtica (Tourn.) Linn. Urticaceae (i). 30 sp. temp, (nettles). Herbs 
with opp. leaves and stipules (sometimes united in pairs between the 
petioles, as in Rubiaceae). The whole plant is usually covered with 
stinging hairs. All the various types of infl. are well illustrated by 
the 3 Brit. sp. In general the infl. is a dichasial cyme with tendency 
to a cincinnus by preference of the / 3 -bracteole (p. 64). In U. pilu- 
lifera L. (Roman nettle) the <? and ? infls. spring side by side from each 
node, the <? catkin-like, the ? a pseudo-head. In U. urens L. (small 
nettle) a panicle is formed containing both <? and ? firs. In U. dioica 
L. (large or common nettle) there is a panicle, but each sex is con- 
fined to its own plant. P 4; A 4, opp. to perianth leaves. The 
sta. are bent down inwards in the bud, and when ripe spring violently 
upwards and bend out of the flr., the anther at the same moment 
turning inside out, so that the loose powdery pollen is ejected as a 
little cloud, and may be borne by the wind to the stigma. The ? flr. 
has a i-loc., i-ovuled ovary with a large brush-like stigma. Achene 
enclosed in the persistent perianth. The young tops are sometimes 
eaten like spinach. Useful fibre can be obtained from the stems of 
the common nettle by maceration. 
Urticaceae. Dicotyledons (Archichl. Urticales). 41 gen. with 460 sp. 
trop. and temp. Most are herbs or undershrubs, with no latex, and with 
alt. or opp. stip. leaves. Infl. cymose often ‘condensed’ into pseudo- 
heads &c. (see Golenkin in Flora , 1894). Firs, usually unisexual 
and regular. P 4 — 5, free or united, sepaloid ; sta. as many, bent 
down inwards in bud and exploding when ripe. Ovary i-loc. with 
1 erect basal orthotropous ovule. Fruit an achene. Seed usually 
with rich oily endosperm; embryo straight. Boehmeria, Urtica, 
Maoutia and others are used as sources of fibre. 
Classification and chief genera (after Engler) : 
A. With stinging hairs. P (4 — 5) in ? . Leaves alt. or opp. 
1. Urereae: Urtica, Urera, Laportea. 
B. No stinging hairs. 
2. Procrideae (stigma paint-brush-like) : Pilea, Pellionia, Ela- 
tostema. 
3. Boehmerieae : Boehmeria, Maoutia. 
4. Parietarieae : Parietaria. 
5. Forskohleeae : Forskohlea. 
[Benth.-Hooker unite Ulmaceae (distinguished by infl., aestivation 
of sta., and ovule) and Moraceae (distinguished by presence of latex, 
and also usually by ovule, embryo, &c.) to Urticaceae, placing the 
order in Unisexuales. Warming places these 3 orders, separated, in 
Urticiflorae] 
Urticales. The 5th cohort of Archichlamydeae (p. 127). 
Urticiflorae (Warming). The 4th cohort of Choripetalae (p. 137). 
Urvillea H. B. et K. Sapindaceae (1). 10 sp. trop. and sub-trop. Am. 
Lianes like Serjania. 
