URTICACELB. 82*J 



Suborder I. VUMACWIJE. (Elm Family.) 



Flowers perfect or moucecitmsly poly^ainous. FilanM'ut.s stralpht or 

 moderately incurved iu the bud. Styles or stigmas 2. Fruit a Haiuara 

 or drupe. — Trees, with alternate leaves. 



1. Ulnms. Flowers sometimes perfect Ovary 2-ovuled. Fruit a samara. Anthe« 



extrorse. 



2. Celtis. Flowers polygamous. Ovary l-ovuled I-Yuit a druiKj. Autht-rs lutrDrec 



Suborder II. UBTICEiE. (Nettle Family.) 



Flowers monoecious or dicjecious. Filaments wrinkled and intlcxod in 

 the bud. Style or stigma siujple. Ovary always I -celled and 1 -seeded, 

 becoming an akene. — Herbs with a tough fibrous bark and opposite or 

 alternate leaves. 



* Calyx iu the fertile flowers of 2 to 5 separate or nearly separate sepals : plant besot with 



stinging bristlea 

 :i. Urtlca. Sepals 4 in both sterile and fertile flowers. Akene straiglit and eit;ot, enrlowrd 

 l)y the 2 inner and larger sepals. Stigma capitate-tufted. Leaves opposite. 



4. Laportea. Sepals 5 in the sterile flowers, 4 in the fertile, or ai>parently only 2, the 



two exterior being minute. Akene very oblique aud bent down, nearly naked. Stigma 

 long and awl-shaped. Leaves alternate. 



* * Calyx of the fertile flowers tubular or cup-shaped, enclosing the akene. Plant wholly 



destitute of stinging bristles. 



5. Parietaria. Flowers polygamous, in involucrate-bracted clusters. Stigma tufl«d. 



Leaves alternate. 



Suborder III. CANNABINE^. (Hemp Family.) 



Flowers dioecious; the sterile raceraed 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, l-ovuled, becoming a glandular akene. — Herbs with opposilo 

 lobed leaves and a fibrous inner bark. 



6. Humulus. Fertile flowers in a short spike forming a membranaceous catkin in fnnt- 



Anthers erect. Leaves 3 to 5-lobed. 



1. ULMUS, L. Elm. 



Calyx bell-shaped, 4 to 9-cleft. Stamon.s 4 to 9, with lone: .^londor fil.imont*. 

 Ovary 2-celled. Fruit winged all r.round. — Flower.>< i)»»ly;.^imi)iis, purplish or 

 yellowish, in lateral clusters, preceding the leavo.«<, which arc strongly stniii;ht- 

 veined, short-petioled, and oblicpie or uno(inally .'*oniewhat heart sha|>od at 

 base. 



1. U. Americana, (L.) "Willd. Buds and hranehlets^dahron.s: J.ranrhon 

 not corky : leaves ol)ovate-oblong or oval, abruptly jiointed, .'»harply and »>fl<»n 

 doubly serrate, soft pubescent beneath or .•<oon t,lahn)U.»«. smooth ulnive »»r 

 nearly so : flowers on slender drooping peduncles which are jointed above the 

 middle, in close fascicles : fruit glabrous except the niargiu.x. it.-i ."^harp point* 



