66 KEY AND FLORA 
4-cleft calyx, 4 stamens, and a rudimentary ovary; pistil- 
late flowers in capitate clusters, calyx 3-4-toothed. Ovary 
stalked; style 2-cleft. Fruit in a globular head.* 
1. B. papyrifera Vent. Paper Murperry. A round-topped tree 
with yellowish-brown bark. Leaves cordate, often irregularly 2-3- 
lobed, serrate, rough above, downy beneath, long-petioled. Staminate 
spikelets peduncled, 2-3 in. long. Pistillate heads stout, peduncled, 
about 1 in. in diameter. Introduced from Asia and very common 8, 
about old dooryards.* 
Iv. CANNABIS L. 
Coarse herbs with very tough, fibrous bark. Leaves usu- 
ally opposite, palmately compound. Flowers small, dicecious, 
greenish, the staminate ones in compound racemes or panicles, 
the pistillate ones in spikes. Calyx of the staminate flowers of 
5 sepals, that of the pistillate flowers of 1 large sepal which 
covers the ovary and the akene. 
1. C. sativa L. Common Hemp. An erect plant, 4-8 ft. high. 
Leaves large, petioled, of 5-7 lanceolate, irregularly serrate or toothed 
leaflets. Cultivated from Europe, 8. and W., for its fiber, and some- 
times runs wild along roadsides in rich soil. 
21. URTICACEZ. Nerrie Famity 
Herbs with watery juice, stem and leaves often clothed with 
stinging hairs. Leaves undivided, stipulate. Flowers small, 
greenish, unisexual, apetalous in axillary clusters. Calyx of 
the staminate flowers 4—5-parted or 4-5-sepalous; stamens as 
many as the sepals and opposite them; filaments inflexed in 
the bud and straightening at maturity ; anthers 2-celled. Calyx 
of pistillate flowers 2-4-sepalous; ovary sessile, 1-celled; 
stigma simple or tufted. Fruit an akene commonly inclosed 
in the dry, persistent calyx.* 
URTICA L. 
Annual or perennial herbs. Leaves with stinging hairs, 
opposite, petioled, several-nerved, dentate or incised, stipulate. 
Flowers moncecious or dicecious. Calyx of the staminate 
