URTICACE^E. (NETTLE FAMILY.) 413 



2. LAPORTEA, Gaudich. 



Flowers monoecious or dioecious. Calyx of the sterile flowers 5-parted. 

 Stamens 5, inserted around the abortive ovary. Calyx of the fertile flowers 

 4-sepalous, the 2 inner ones larger. Stigma subulate, hairy on one Bide. 

 Achcnium oblique, tubercular-roughened. — Herbs, with stinging hairs, alter- 

 nate long-petioled serrate leaves, and minute flowers in spreading cymes. 



1. L. Canadensis, Gaudich. Stem hispid ; leaves ovate, acuminate, 

 rounded or cordate at the base ; the veins and petioles hispid ; cymes very 

 Blender, single or by pairs, the upper mostly fertile, the lower sterile. (Urtica 

 Canadensis and U. divaricate, L.) — Low shaded places, Florida, and north- 

 ward. July and Aug. y. — Stem 2° -4° high. 



3. PILEA, Lindl. 



Flowers monoecious or dioecious. Calyx of the sterile flower 3 - 4-partcd. 

 Stamens 3-4. Calyx of the fertile flowers 3-lobed, the lobes unequal or nearly 

 equal, commonly with an indexed scale-like sterile stamen at the base of each. 

 Stigma sessile, tufted. Achcnium ovate, compressed, straight. — Low herbs, 

 destitute of stinging hairs. Leaves opposite, long-petioled. Flowers in axillary 

 cymose clusters. 



1. P. pumila, Gray. Stem angular, simple, smooth, pellucid; leaves 

 membranaceous, ovate or elliptical, acuminate, coarsely serrate, 3-nerved, slight- 

 ly hairy above ; cymes much shorter than the petiole. (Urtica pumila, L.) — 

 Wet shaded places, Florida, and northward. July- Sept. (T) — Stem 6' -12' 

 high. Upper leaves l'-2' long, the lower not longer than the petiole. 



2. P. heraiarioides, Lindl. Stems erect or creeping, branched, tender, 

 pellucid ; leaves small, round-obovate, entire, opaque, transversely marked on 

 the upper surface with white raised lines ; clusters shorter than the petiole ; 

 flowers minute. — Shaded moist places, Key West. November. — Stems 2' -4' 

 long. Leaves l"-2" long, rather longer than the petiole. Achenium very 

 minute, oblong, terete. 



4. PARIETARIA, Tourn. Pellitory. 



Flowers polygamous, in axillary cymose clusters, supported by a bract-like 

 involucre. Calyx of the sterile flowers 4 - 5-sepalous. Stamens 4-5, inserted 

 around the abortive ovary. Calyx of the fertile flowers 4-parted. Stigma 

 tufted. Ovary surrounded by four sterile, or sometimes perfect, stamens. Ache- 

 nium ovoid. — Weak downy herbs, without stinging hairs. Leaves alternate, 

 entire, long-petioled. Flowers minute, greenish. 



1. P. Pennsylvanica, Mnbl Pubescent with straight hairs; stem sim- 

 ple or sparingly branched ; leaves thin, oblong-lanceolate, obtuse, roughened 

 with minute elevated dots; clusters dense; flowers shorter than the involucre. 

 — Shaded rocks in the upper districts. May-July. Q) — Stem 4'- 12' high. 



Leaves 6"- 9" longr. 



