436 iKTicACK-K. (nktti.i: 1 amilv.) 



2. LA.PORTEA, (ian.li.l.. 



Flowers nioiicecious or dia-cious. C;il_v.\ of tlio sterile flowers S-parted. 

 Stamens 5, inserted aruiind the abortive ovary. C'alvx of the fertile tlowers 

 4-sei)aluus, the 2 inner sejiais larger. Stigma siil)ulate, hairy on one side. 

 Ailieniiini ol>li(|Ue, tuherc-niar-roughciicd. — Herbs, with stinging hairs, alter- 

 nate liing-petioled serrate leaves, and minute (lowers in spreading cymes. 



1. L. Canadensis, (Jandich. stem hispid; leaves ovate, acuminate, 

 rounded or curdato at tlie base; tiic veins and petioles hispid; cymes very 

 slender, single or by pairs, tlie »|)per mostly fertile, tiie lower sterile. — Low 

 shaded places, Florida, and northward. .July- August. % — Stem 2°-4° 

 high. 



3. PILEA, Liudl. 



Flowf^rs mona'cious or di(P(icms. Caly.x of the sterile flower 3-4-parted. 

 Stamens3-4. Caly.x of tlie fertile flowers 3-lobed, tiie lobes uneipial or nearly 

 equal, commonly witii an infle.xed scale-like sterile stamen at tlie ba.se of each. 

 Stigma se.<sile, tufted. Achenium ovate, compressed, straight. — Low lierlis, 

 destitute of stinging hairs. Leaves opposite, long petioled. Flowers iu axil- 

 lary cymose clusters. 



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

 membraiiaicDiis, ovate or elliptical, acuminate, coarsely serrate, 3nerved, 

 slightly hairy above; cymes mucli shorter tlian tiie petiole. — Wet shaded 

 places. July - Sept. (T) — Stem 6' - 1 2' higli. Upper leaves 1' - 2' long, the 

 lower not longer tiiaii tlie petiole. 



2. P. herniarioides, Lindl. Stems erect or creeping, branched, ten- 

 der, jjclhuid ; leaves small, round-obovate, entire, opaque, transversely marked 

 on the u])per surface with wliite raised lines ; clusters shorter than the peti- 

 ole; flowers minute. — Shaded moist places. Key West. Nov. — Stems 2' -4' 

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

 minute, oblong, terete. 



4. PARIETARIA, Tourn. Peli.itokt. 



Flowers jiolygamous, 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. 

 Achenium ovoid. — Weak downy herbs, without stinging hairs. Leaves al- 

 ternate, entire, long-p^tioled. Flowers minute, greenish. 



1. P. Pennsylvanica, Muhl. Pubescent with straigbt hairs; .stem 

 simple or s])aringly branched ; leaves thin, oblong-lanceolate, obtuse, rough- 

 ened with minute elevated dots; clusters dense;- flowers shorter than the 

 involucre. — Shaded rocks in the upper districts. May -July. (T) — Stem 

 4'- 12' high. Leaves 6" - 9" long. 



2. P. debilis, Forst. Pubescent with straight and hooked hairs inter- 

 mixed ; stem much branched, pellucid ; leaves ovate, mostly acuminate, but 

 obtuse, roughened with elevated dots; clusters loose, spreading ; flowers as 



