106 URTICACEAE. 



in some genera partly amphitropous. Fruit an achene. Endosperm oily, 

 usually not copious; embryo straight. About 40 genera and 550 species 

 of wide geographic distribution. 



Herbs with stinging hairs. 1. Fleurya. 

 Herbs without stinging hairs. 



Stigma penicellate. 2. Pilea. 



Stigma not penicellate. 3. Rousselia. 



1. FLEURYA Gaud. Bot. Voy. Freyc. 497. 1830. 



Annual herbs, with stinging hairs similar to those of nettles, alternate 

 petioled dentate leaves, and minute clustered monoecious or dioecious flowers. 

 Staminate flowers with a 4-5-parted perianth, 4 or 5 stamens and a rudimentary 

 ovary. Pistillate flowers with 4 imbricated perianth-segments, a somewhat 

 oblique ovary, the stigma papillose ; ovule erect. Fruit an oblique achene. 

 [Commemorates J. F. Fleury, French botanist.] About 8 species, of tropical 

 regions. Type species: Fleurya paniculata Gaud. 



1. Fleurya aestuans (L.) Gaud.; Griseb. Fl. Br. W. I. 154. 1859. 

 Urtica aestuans L. Sp. PI. ed. 2, 1397. 1763. 



Erect or ascending, simple or little-branched, 3-9 dm. high, the stinging 

 hairs copious or few. Leaves thin, ovate or ovate-orbicular, 2-12 cm. broad, 

 coarsely and sharply dentate, acute or acuminate at the apex, rounded or sub- 

 cordate at the base, the petioles 1-10 cm. long; panicles androgynous, shorter 

 than or equalling the leaves, slender-peduncled ; achene ovate, compressed, about 

 2.5 mm. long. 



A weed in waste places. New Providence at Nassau and Grant's Town : 

 Haiti to Tortola and Trinidad ; Jamaica ; continental tropical America. WEST IN- 

 DIAN NETTLE, COW-ITCH. 



2. PILEA Lindl. Coll. pi. 4. 1821. 



Herbs, with opposite petioled mostly 3-nerved leaves, connate stipules, and 

 small monoecious or dioecious flowers in axillary clusters. Staminate flowers 

 mostly 4-parted (sometimes 2- or 3-parted) and with a rudimentary ovary. 

 Pistillate flowers 3-parted, the segments in most species unequal, each subtend- 

 ing a staminodium in the form of a concave scale; ovary straight; stigma 

 sessile, penicillate. Achene compressed. Seed-coat thin. Endosperm scanty 

 or none. [Name unexplained.] About 160 species, chiefly in the tropics, most 

 abundant in tropical America. Type species: Pilea muscosa Lindl. 



Leaves firm, thick or succulent ; stems erect. 1. P. microphylla. 



Leaves very thin and flaccid, slender-petioled ; stems prostrate. 2. P. tenerrima. 



1. Pilea microphylla (L.) Liebm. Yid. Selsk. Skr. V. 2: 296. 1851. 



Parietaria microphylla L, Syst. ed. 10, 1308. 1759. 

 Pilea muscosa Lindl. Coll. pi. 4. 1821. 



Annual or biennial, slender, glabrous. Stems erect or ascending, or some- 

 times creeping at the base, 5-30 cm. long, fleshy, simple or mostly branched; 

 leaves elliptic or oblanceolate, 410 mm. long, acute or acutish at the apex, 

 entire, acuminate at the base, transversely wrinkled; petioles filiform, shorter 

 than the blades; flower-clusters very small, shorter than the petioles; sepals 

 ovate, very thin, acutish; achenes oblong, lenticular. 



On walls and in waste rocky places, New Providence, Eleuthera, Great 

 Exuma : Bermuda ; Florida ; West Indies ; continental tropical America. LACE- 

 PLANT. 



