268 CXXIIIp. URTICACEH (Rendle). [ Pilea. 
thin ; albumen almost none ; cotyledons broad.—Annual or peren- 
nial herbs, sometimes shrubby at the base. Leaves opposite, stalked, 
those of a pair equal or unequal, entire or toothed, 3-nerved. Sti- 
pules connate into one, intrapetiolar. Flowers in axillary 1-sexual 
or 2-sexual cymes; cymes sessile or stalked, sometimes densely 
capituliform, sometimes paniculate. 
Species about 200, widely distributed throughout the tropics. 
Leaves of a pair markedly unequal, elliptic, margin 
entire ... “0 ope soe seit Sak she 
Leaves of a pair generally subequal, ovate or lanceo- 
late (elliptic in 13, P. wsambarensis), margim 
serrate or crenate-serrate. 
Flowers forming false sessile whorls at the nodes ..._ 2. P. ceratomera. - 
The four uppermost leaves forming an apparent 
whorl subtending a cruciate dense inflorescence 3. P. tetraphylla. 
Flowers not in false whorls at the nodes nor specially 
associated with the uppermost leaves. 
Inflorescence much shorter than the petioles; 
flowers crowded in dorsiventral cymules 
1. P. manniana. 
which are sometimes very reduced ... .... 4. P. angolensis. 
Inflorescence generally laxly paniculate or dicho- 
tomous. i S 
Plant shrubby _... was a See ... 5. P. urticefolia. 
Plant a herb. 
Leaves ovate. 
Plant 24 ft. high; lateral pair of nerves i 
reaching to base of leaf-tip ... ... 6. P. Holstir. 
Plant $ to 14 ft. high ; lateral pair of nerve 
ceasing well below the base of leaf-tip 7. P. sublucens. 
Leaves lanceolate ee oe ae ... 8. P. bambuseti. 
Flowers contracted into one or more stalked heads. 
Leaves ovate. 
Achene ovate. 
Stipules membranous, persistent ... oer Os Es Johnstoni. 
Stipules deciduous ... es See ... 10. P. veronicifolia. 
Achene lenticular éoi we as . Ll. P. Getz. 
Leaves lanceolate... Sea eee es ... 12. P. Engleri. ; 
Leaves elliptic... sui ws is ... 13. P. usambarensis. 
Leaves trapeziform A cau a ... 14. P. kiwuensis. 
1. P. manniana, Wedd. in DC. Prodr. xvi. i. 117. Dicecious, 
somewhat shrubby, apparently climbing, glabrous. Stem terete, 
smooth ; internodes 2-4 in. long. Leaves of a pair unequal, oblong- 
elliptic to elliptic, acuminate, the larger petiolate, 3-6 in. long am 
14-3 in. wide, with a rounded base, the smaller subsessile, 2-3 12. 
long, 1-1} in. wide, with a cordate somewhat amplexicaul base, 
margin subentire or inconspicuously serrulate below the apex; tripli- 
nerved, nerves prominent beneath and joined by conspicuous curving 
secondary veins, network of veins also prominent, the meshes bearing 
numerous minute linear cystoliths ; petiole of larger leaf 13-13 ™- 
long. Stipules oblong-ovate, deciduous, about 5 lin. long. Cymes 
