330 URTICACE^E. 



incurved and closing the notch. — In the Atlantic States, and extending within 

 our boundary through Minnesota. Known as " American" or " White Elm." 



2. CELTIS, Tourn. Hackberrt. 



Calyx 5 to 6-parted. Stamens 5 to 6. Ovary 1-celled. Fruit globular. 

 — Leaves pointed, petioled : flowers greenish, axillary, the fertile solitary 

 or in pairs, peduncled, appearing with the leaves; the lower usually staminate 

 only, in little fascicles or racemose along the base of the branches of the 

 season. 



1. C. OCCidentalis, L. Leaves reticulated, ovate, cordate-ovate and 

 ovate-lanceolate, taper-pointed, sharply serrate, sometimes sparingly so or 

 only towards the apex, scabrous but mostly glabrous above, usually soft- 

 pubescent beneath, at least when young: fruit reddish or yellowish, becoming 

 dark purple. — From Colorado to Wisconsin and eastward. A small or mid- 

 dle-sized tree with the aspect of an elm. 



3. URTICA, Tourn. Nettle. 



Flowers clustered, the clusters mostly in racemes, spikes, or loose heads. 

 Stamens in the fertile flowers inserted around the cup shaped rudiment of a 

 pistil. — Flowers greenish. Ours are perennials with flower clusters in pani- 

 cles or pauicled spikes. 1 



1. U. gracilis, Ait. Sparingly bristly, slender: leaves ovate-lanceolate, 

 serrate, 3 to 5-nerved from the rounded or scarcely heart-shaped base, almost 

 glabrous, the elongated slender petioles sparingly bristly : spikes slender and loosely 

 panicled. — Colorado and northward, thence eastward across the continent. 



2. U. Breweri, Watson. Tall and stout, grayish with a short somewhat 

 hispid pubescence, or nearly glabrous, and with scattered bristles : leaves thin, 

 finely pubescent, soon glabrate or roughish above, ovate to oblong-lanceolate, 

 rounded or slightly cordate at base, coarsely serrate, on slender petioles : flowers 

 in short open panicles scarcely exceeding the petioles. — Proc. Amer. Acad. x. 348. 

 Ranging from S. California to S. Colorado and Texas. 



3 U. holosericea, Nutt. Tall and stout, more or less bristly, finely and 

 densely tomentose especially on the lower side of the leaves: leaves thick, oblong- 

 to ovate-lanceolate, rounded at base, on short stout petioles: staminate flowers 

 in loose slender diffuse panicles nearly equalling the leaves; pistillate panicles 

 denser and shorter. — U. dioica, var. occidentalis, Watson, Bot. King Exped. 

 Abundant in ihe Wasatch and westward throughout California. 



4. LAPORTEA, Gaudichaud. Wood-Nettle. 



Flowers clustered in loose cymes ; the upper widely spreading and chiefly 

 or entirely fertile; the lower mostly sterile. — Herbs with large alternate ser- 

 rate leaves, and axillary stipules. 



1 U. dioica, L., is very bristly and stinging, with leaves ovate, heart-shaped, very deeply 

 serrate, downy underneath, and the spikes much branched. — Introduced into Colorado and 

 elsewhere from the East, where it has come from Europe. 



