UBTICACE^E. (NETTLE FAMILY.) 395 



axis of albumen. Herbs (or in the tropics often shrubs or trees), with a 

 watery (innocuous) juice, a tough fibrous bark, and opposite or alternate 

 leaves : many are armed with stinging hairs. 



* Calyx of the fertile flowers of 2 - 4 separate or nearly separate sepals. 

 i- Plant beset with stinging bristles. 



5. URTICA. Sepals 4 in both sterile and fertile flowers. Achenium straight and erect, en- 



closed by the 2 inner and Ifijrger sepals. Stigma capitate-tufted. Leaves opposite. 



6. LAPORTEA. Sepals 5 in the sterile flowers, 4 in the fertile, or apparently only 2, the two 



exterior minute and obscure Achenium very oblique and bent down, nearly naked. 

 Stigma long and awl-shaped LeaTes alternate. 



- - Plant wholly destitute of stinging hairs. 



7. PILEA. Sepals 3 or 4, those of the fertile flowers all or all but one small. Achenium 



partly naked, straight and erect. Stigma pencil-tufted. Leaves opposite. 

 * * Calyx of the fertile flowers tubular or cup-shaped, enclosing the achenium. 



8. BQJHMERIA. Flowers monoecious, glomerate, the clusters spiked, not involucrate. Style 



long and thread-shaped, stigmatic down one side. 



9. PARIETARIA. Flowers polygamous, hi involucrate-bracted clusters. Stigma tufted. 



SUBORDER IV. CANNABINE^E. THE HEMP FAMILY. 



Flowers dioecious ; the sterile racemed or panicled ; the fertile in clus- 

 ters or catkins. Filaments short, not inflexed in the Bud. Fertile calyx 

 of one sepal, embracing the ovary. Stigmas 2, elongated. Ovary 1-celled, 

 with an erect orthotropous ovule, forming a glandular achenium in fruit. 

 Seed with no albumen. Embryo coiled or bent. Herbs with a watery 

 juice and mostly opposite lobed or divided leaves, a fibrous inner bark, &c. 

 (yielding bitter and narcotic products). 



10. CANNABIS. Fertile flowers spiked-clustered. Anthers drooping. Leaves 5 - 7-divided. 

 11 HUMULUS Fertile flowers in a short spike forming a membranaceous catkin in fruit 

 Anthers erect. Leaves 3 - 5-lobed. 



SUBORDER I. ULUlACEJE. THE ELM FAMILT. 



1. L-UIUS, L. ELM. 



Calyx bell-shaped, 4 - 9-cleft. Stamens 4-9, with long and slender filaments. 

 Ovary 1 - 2-celled, with a single anatropous ovule suspended from the summit 

 of each cell: styles 2, short, diverging, stigmatic all along the inner edge. 

 Fruit (by obliteration) a 1-ccllcd and 1-seeded membranaceous samara, winged 

 all around. Albumen none : embryo straight ; the cotyledons large. Flowers 

 perfect or polygamous, pu-plish. or yellowish, in lateral clusters, in our species 

 preceding the leaves, which are strongly straight-veined, short-petioled, and 

 oblique or unequally somewhat heart-shaped at the base. Stipules small, cadu- 

 cous. (The classical Latin name.) 

 * Flowers appearing nearly sessile : fruit orbicular, not ciliate : leaves very rough above. 



1. U. fiilva, Mich. (SLIPPERY or EED ELM.) Buds before expansion 

 soft-downy with rusty hairs (large) ; leaves ovate-oblong, tape"-t>oin<cd, doubly 

 serrate (4' -8' long, sweet-scented in drying), soft-downy underneath or slightly 



