URTICACE.E. 199 



SUBORDER III. URTI'CEjE. (NETTLE FAMILY.) 



Herbs with watery juice and opposite or alternate leaves, 

 often beset with stinging hairs. Flowers monoecious or 

 dioecious, in spikes or racemes. Stamens as many as the 

 sepals. Style only 1. Ovary 1-celled. Fruit an achene. 



4. Urti'ca. Leaves opposite. Plant beset with stinging hairs. Sepals 



4 in both sterile and fertile flowers. Stamens 4. Stigma a small 

 sessile tuft. Achene flat, enclosed between the 2 larger sepals. 

 Flowers greenish. 



5. Laport'ea. Leaves alternate. Plant beset with stinging hairs. 



Sepals 5 in the sterile flowers, 4 in the fertile, 2 of them much 

 smaller than the other 2. Stigma awl-shaped. Achene flat, very 

 oblique, reflexed on its winged pedicel. 



6. Pil'ea. Leaves opposite. Whole plant very smooth and semi-trans- 



parent. Sepals and stamens 3-4. Stigma a sessile tuft. 



7. Boeluuc'ria. Leaves mostly opposite. No stinging hairs. Sepals 



and stamens 4 in the sterile flowers. Calyx tubular or urn-shaped 

 in the fertile ones, and enclosing the achene. Stigma long and 

 thread-like. 



8. Parleta'ria. Leaves alternate, entire, 3-ribbed. No stinging hairs. 



Flowers polygamous, in involucrate-bracted cymose axillary clus- 

 ters. Calyx of the pistillate flowers tubular or bell-shaped, 4-lobed. 

 Stigma tufted. Staminate flowers nearly as in the last. 



SUBORDER IV. CANNABIN'E^l. (HEMP FAMILY.) 



Bough herbs with watery juice and tough bark. Leaves 

 opposite and palmately divided or lobed. Flowers dioecious. 

 Sterile ones in compound racemes ; stamens 5 ; sepals 5. 

 Fertile ones in crowded clusters ; sepal only 1, embracing 

 the achene. Stigmas 2. 



9. Can'uabis. A rather tall rough plant with palmately compound 



leaves of 5-7 linear-lanceolate serrate leaflets. Fertile flowers 

 spiked-clustered. 



16. II urn ii I us. Leaves 3-5-lobed. Plant climbing. Fertile flowers in 

 a short spike, forming a membranaceous catkin in fruit. 



1. ULMUS, L. ELM. 



1. U. fulva, Michx. (BED or SLIPPERY ELM.) Flowers 

 nearly sessile. Leaves very rough above, taper-pointed. Buds 

 downy with rusty hairs. A medium-sized tree, with muci- 

 bginous inner bark. ' 



