URTICACE^E. (NETTLE FAMILY.) 441 



many as the lobes of the calyx and opposite them, or sometimes fewer. Coty- 

 ledons usually broad. Stipules often deciduous. A large order (far the 

 greater part tropical), comprising the following suborders, viz. : 



SUBORDER I. UL,UIACEjE. ELM FAMILY. ^ 



Flowers perfect or moneeciously polygamous. Filaments straight or 

 moderately incurved in the bud. Styles or stigmas 2. Fruit a samara 

 or drupe. Seed suspended. Trees, with a watery juice (no active or 

 noxious properties), and alternate leaves. 



* Fruit dry, winged or crested (a samara) : anthers extrorse. 



1. Ulmus. Flowers sometimes perfect. Ovary 2-ovuled. Fruit 1-celled, winged. 

 2. . Plauera. Flowers polygamous. Ovary 1-ovuled. Fruit wingless, nut-like. 



* * Fruit a drupe : anthers introrse. 



3. Celtis. Flowers polygamous. Ovary 1-ovuled. Cotyledons curved and crumpled. 



SUBORDER II. ARTOCARPE.E. BREAD-FRUIT & FIG FAMILY. 



Flowers monoecious or dioecious, crowded in catkin-like spikes or heads ; 

 the calyx, &c. becoming fleshy or juicy in fruit, but the 1- (rarely 2-) 

 celled ovary ripening as a dry achenium. Styles or stigmas commonly 2. 

 Mostly trees or shrubs, with a milky or yellow (acrid or poisonous) 

 juice, and alternate (rough or smooth) leaves. Stamens inflexed in 

 the bud, and elastically spreading when the flower opens, in the Tribe 

 MOREJE. 



4. Morns. Fertile and sterile flowers in separate spikes. Calyx berry-like in fruit. 



SUBORDER HI. URTICE^E. NETTLE FAMILY. 



Flowers monoecious or dioecious. Filaments transversely wrinkled and 

 inflexed in the bud, straightening or spreading elastically when the flower 

 opens. Style or stigma simple. Ovary always 1-celled, with an erect or- 

 thotropous ovule, forming an achenium in fruit. Embryo straight in the- 

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

 watery bland juice, a tough fibrous bark, and opposite or alternate leaves: 

 many ar6 armed with stinging hairs. 



* Calyx in the fertile flowers of 2 - 5 separate or nearly separate sepals. 

 - 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 larger 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. Leaves alternate. 



H- - Plant wholly destitute of stinging bristles. 



7. Pllea. Sepals 3 or 4, those of the fertile flowers unequal, all or all but one small- 



Achenium partly naked, straight and erect. Stigma pencil-tufted. 



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

 8. Boehmeria. Flowers monoecious, glomerate, the clusters spiked, not involucrate. 



Style long and thread-shaped, stigmatic down one side. 

 9. Parie taria. Flowers polygamous, in involucrate-bracted clusters. Stigma tufted. 



