Jones: Flora of Illinois, 47. Santalaceae 113 



46. Urticaceae Reichenb. — Nettle Family 



1. Leaves mostly opposite. 



2. Plants with stinging hairs, perennial; stigma capitate-tufted I. Urtica 



2. Plants without stinging hairs. 



3. Plants perennial, more or less pubescent; stems opaque; petioles usually somewhat 



shorter than the blades; stipules separate; stigma filiform 2. Boehnteria 



3. Plants annual, glabrous; stems translucent; blades glossy above, about as long 



as the petioles; stipules united; stigma capitate-tufted 3. Pilea 



1 . Leaves alternate. 

 4. Plants with stinging hairs; leaves ovate, 5-12 cm. broad; flowers in loose branched 



cymes 4. Laporlea 



4. Plants without stinging hairs; leaves lanceolate, less than 2.5 cm. wide; flower 

 clusters sessile in the leaf-axils 5. Parietaria 



1. Urtica L. — Nettle 



1. Plants perennial, 0.5-3 m. tall; flower-clusters in branched paniculate spikes. 

 2. Leaves lanceolate, firm, not cordate at base; alluvial soil, chiefly in the n. 

 half of th'e state. July- Aug. [U. gracilis sensu auth., non Ait.} Com- 

 mon Nettle U. procera Muhl. 



2. Leaves ovate-lanceolate or ovate, coarsely serrate, thin, cordate or rounded 

 at base; waste places and roadsides, not common; nat. from Eur. July- 

 Sept. Great Nettle ^- d'^oica L. 



1. Plants annual, 10-40 cm. tall; flower-clusters simple, two in each leaf-axil; 

 leaves oval or ovate, 1-4 cm. long, acute, coarsely serrate or incised; waste 

 places; nat. from Eur. May-Sept. Small Nettle U. urens L. 



2. BoEHMERiA Jacq. — False Nettle 

 B. cylindrica (L.) Sw. Moist woods. July- Aug. 



3. PiLEA Lindl. — Clearweed 



1 . Fruit ovate, gt^en, irregularly roughened, purplish-marked, not margined; 

 moist shaded ground, common. July-Sept P. pumila (L.) Gray 



1. Fruit shortly lanceolate, dull brownish, smooth, with a distinct narrow mar- 

 gin; moist ground rare. July-Sept P. fontaiia (Lunell) Rydb. 



4. Laportea Gaud. 



{Urlicastrum Fabr.) 

 L. canadensis (L.) Gaud. Wood Nettle. Woods, common. July-Aug. 



5. Parietaria L. — Pellitory 

 P. pennsylvanica Muhl. Woods, common. May-Sept. 



47. Santalaceae R. Br. — Sandalwood Family 



1. Comandra Nutt. 



C. umbellata (L.) Nutt. Sandy soil or grassy roadsides, local. May-June. 

 [C. richardsiana Fern.] 



