672 URTICA 



L. (small nettle) a panicle is formed containing both i and ? fls. 

 In U. dioica L. (large or common nettle) there is a panicle, but each 

 sex is confined to its own plant. P 4; A 4, opp. to P leaves. The sta. 

 are bent down inwards in the bud, and when ripe spring violently up- 

 wards and bend out of the fl., the anther turning inside out, so that 

 the loose powdery pollen is ejected as a little cloud, and may be borne 

 by wind to the stigma. The ? fl. has a i-loc., i-ovuled ovary with a 

 large brush-like stigma. Achene enclosed in the persistent P. Young 

 tops eaten like spinach. Useful fibre from stems. 



Urticaceae (EP. ; BH. incl. Moraceae, Ulmaceae, Cynocrambaceae}. 

 Dicots. (Archichl. Urticales). 41 gen., 480 sp., trop. and temp. Most 

 are herbs or undershruhs, with no latex, and with alt. or opp. slip. 1. 

 Intl. cymose often ' condensed ' into pseudo-heads, &c. Fls. usu. uni- 

 sexual and reg. P 4 5, free or united, sepaloid; sta. as many, bent 

 down inwards in bud and exploding when ripe; G i-loc. with i erect 

 basal orthotr.ov.and i style. Achene. Seed usu. with rich oilyendosp.; 

 embryo straight. Boehmeria, Urtica, Maoutia and others are used as 

 sources of fibre. 

 Classification and chief genera (after Engler) : 



A. With stinging hairs. P (45) in ? . L. alt. or opp. 



1. Ureieae: Urtica, Urera, Laportea. 



B. No stinging hairs. 



2. ProcriJeae (P of ? 3-merous, stigma paint-brush-like): Pilea, 

 Pellionia, Elatostema. 



3. Boehmerieae ( i usu. with 45 sta. No invol.): Boehmeria, 

 Maoutia. 



4. Parielarieae (P present ; bracts often united in invol. ) : Parie- 

 taria. 



5. Forskohleeae ( 3 fl. reduced to ( sta.). 



Ulmaceae are distinguished by infl., aestivation of sta., and ovule, 

 and Moraceae by presence of latex, and also usu. by ovule, embryo, 



&c. 



Urticales. The 1 2th order of Archichlamycleae. 



Urticastrum Fabricius = Laportea Gaudich. (Urtic. ). 



Urticiflorae (Warming). The 4th order of Choripetalae. 



Urucury nut, Maximiliana. 



Urvillea H. B. et K. Sapind. (i). 10 warm Am. Lianeslike Serjania. 



Usteria Willd. Loganiaceae. i trop. W. Afr. 



Ustilago antherarum, Lychnis. 



Utleria Bedd. Asclepiadaceae (i). i S. India. 



Utricle, Cyperaceae. 



Utricularia L. Lentibulariaceae. 210 trop. and temp., the latter all 

 aquatic. Some Brazilian sp. are confined to the pitchers of the Brome- 

 liaceae. 3 in Brit. ; U. vulgaris L., the bladder-wort, common. 

 The morphology is intere.-ting, for the usual distinctions drawn be- 

 tween root, stem and 1. cannot be applied here. The common bladder- 

 wort is a submerged water pi. with finely-divided 1. ; it never has 

 roots, even in the embryo. The fls. project above water on short 

 shoots, and there are also short shoots with small 1., which arise from 

 the main axis and grow upwards to the surface. Upon the ordinary 

 submerged 1. are borne the bladders, curious hollow structures with 



