IRTICACE.IC. (NKTTLK FAMILY.) 405 



the cu])-8hapeLl rudiment of a pistil. Fert. Fl. Sepals 4, in pairs; the 2 outer 

 smaller autl spreading ; the 2 inner flat or coucave, in fruit niemhranaceous 

 and enclosing the straight and erect ovate flattened achene. Stigma sessile, 

 capitate and pencil-tufted. — Herbs, armed with stinging hairs. Leaves oppo- 

 site ; stipules in our speties distinct. Flowers greenish; in summer. (The 

 classical Latin name; from uru, to burn.) 



* Perennidls ; Jloiccr-clnsters ui branckiufj panirled sjilkes, often dutrinns. 



\. U. gracilis, Ait. Sparinr/li/ bristhj, slender (2 - 6° high) ; leaves ovdtr- 

 lanrcolale., pointed, serrate, 3 - 5-nerved from the rounded or scarcely heart- 

 shaped base, almost glabrous, the elongated slender petioles sparinglfi bristly ; 

 spikes slender and loosely panided. — Feuce-rows and moist ground, common. 

 Stings few. 



U. DloiCA, L. Verif bristl// and stinging (2-3° high); leaves ovate, heart- 

 shaped, pointed, veri/ deeplg serrate, doivni/ beneath as well as the upper jjart 

 of the stem ; spikes'mnrh branched. — Waste places and roadsides, ratlier rare. 

 Canada and N. Eug. to S. C, west to Minn, and Mo. (Nat. from Eu.) 



* * Atinuals ; Jioicer-clusters chiejlj axillary and shorter than the petiole, andro- 



gi/nous. 



U. tiRExs, L. Leaves elliptical or ovate, very coarsely and deeply serrate 

 with long spreading teeth, the terminal teeth not longer than the lateral ones ; 

 f.ower-clusters 2 in each axil, small and loose. — Waste grounds, near dwellings, 

 eastward ; scarco. Plant 8-12' high, with sparse stings. (Nat. from Eu.) 



2. U. Chamsedryoides, Pursh. Leaves ovate and mostly heart-shaped, 

 the u])per ovate-lanceolate, coarsely serrate-toothed ; Jloiver-chisters globular, 

 1 - 2 in each axil, and spiked at the summit. — Alluvial shaded soil, from Ky. 

 to the Gulf States. Slender, 6-30' high, sparsely beset with stings. 



9. LAPORTEA, Gaudichaud. Wood-Nettle. 



Flowers monoecious or dicjccious, clustered, in loose cymes; the upper widely 

 spreading and chiefly or entirely fertile ; the lower mostly sterile. Ster. Fl. 

 Sepals and stamens 5, with a rudiment of an ovary. Fert. Fl. Calyx of 4 

 sepals, the two outer or one of them usually minute, and the two inner much 

 larger. Stigma elongated awl-shajied, hairy down one side, persistent. Achene 

 ovate, flat, extremely oblique, reflexed on the winged or margined pedicel, 

 nearly naked. — Perennial herbs, with stinging hairs, large alternate serrate 

 leaves, and axillary stipules. (Named for M. L.aporte.) 



1. L. Canadensis, Gaudichaud. Stem 2-3° high ; leaves ovate, pointed, 

 strongly feather-veined (3 - 7' long), long-petioled ; fertile cymes divergent; 

 stipule single, 2-cleft. — Moist rich woods. .July - vSept. 



10. PI LEA, Lindl. Richweed. Clearweed. 



Flowers monwcious or dirvcious. Ster. Fl. Sepals and stamens 3-4. Fert. 

 Fl. Sepals 3, oblong, more or less unequal ; a rudiment of a stamen com- 

 monly before each in the form of a hooded scale. Stigma sessile, pencil-tufted. 

 Achene ovate, compressed, erect, partly or nearly naked. — Stingless, mostly 

 glabrous and low herbs, with opposite leaves and united stipules ; the stami- 

 uate flowers often mixed with the fertile. (Named from the shape of the 

 larger sepal of the fertile flower in the original sj>ecies. which |)artly covers 

 the achene, like the pileus, or felt cap, of the Romans.) 



30 



