140 CL. AROIDE.E (browx). [Pistia. 



1. PISTIA, Linn.; Benth. et Hook. f. Gen. PI. iii. 964. 



Spathe small, tubular below , limb open, oblique, constricted on 

 each side at its base. Spadix shorter than the spathe, monoecious ;. 

 female part adnate to the back of the spathe ; male part free, stipitate, 

 having two neuter organs at its base, the upper cup-shaped or frill-like, 

 the lower suborbicular or subreniform in outline, with the sides bent 

 inwards or downwards. Flowers unisexual. Perianth none. Female 

 inflorescence of a single ovary, apparently arising from the back of the 

 spathe, very oblique, 1 -celled ; style obliquely erect from the top of the 

 ovary ; stigma capitate ; ovules numerous, basal, orthotropous. Male 

 inflorescence of a stipitate whorl of 3-8 flowers ; each flower composed 

 of 2 connate 2-celled anthers, opening by short slits. Fruit ellipsoid, 

 with a thin pericarp, many-seeded. Seeds cylindric- oblong, truncate at 

 each end, depressed at the apex, with an operculum closing the micro- 

 pyle, rugulose ; testa thick, composed of a brown membranous outer 

 and inner skin, and a thick white cellular layer between them ; embryo 

 minute, apical. — A floating, stoloniferous, stemless herb, with a tuft of 

 fibrous roots. Leaves in a rosette; veins flabellate, raised beneath. 

 Spathes axillary, with very short peduncles. 



A genus of one species, very variable in the form of its leaves, found throughout 

 the tropical and sub-tropical regious of the globe, in still, fresh water. 



1. P. Stratiotes, Lrmi. Sp. PI. ed. 1, 963. Leaves sessile in a 

 rosette, 1-5 in. long, 1-2 in. broad, cuneate-oblong cr cuneate-obovate,. 

 notched or entire at the broadly rounded or subtruncate apex, more or 

 less pubescent on both surfaces, tomencose with long matted hairs at 

 the base. Spathe 3^-5 lin. long, more or less hairy or villous outside, 

 glabrous within, pale green ; limb ovate, subobtuse, with a broad white 

 cilioiate margin. Ovary pale green, pubescent. Neuter organs frill- 

 like, pale green. Anthers dirty white. — Diet. Sciences Nat. ix. 537, 

 xli. 154, PI. ii. tt. 7-8; Hook. Niger Fl. 527; Bot. Mag. t. 4564; 

 Flore des Serres, vi. 289, t. 625; Thompson in Speke, Nile, Append. 

 651 ; Oliver in Trans. Linn. Soc. xxix. 159 ; Engl, in DC. Monogr. 

 Phan. ii. 634 ; Pflanzenfam. ii. iii. 152, fig. 100; Jahrb. vii. 332; and 

 Pfl. Ost-Afr. C, 132 ; Baill. Hist, des PI. xiii. 449, fig. 323-327 ; N. E. 

 Br. in Dyer, Fl. Cap. vii. 33 ; Durand & Schinz, Conspect. Fl. Afr. v. 

 483, 484, and Etudes Fl. Congo, i. 277; De Wild. & Durand, Contrib. 

 Fl. Congo, i. fasc. 2, 65 ; Hofim. in Bolet. Sec. Brot. iv. 233 ; Rendle 

 in Cat. Afr. PI. Welw. ii. 85; Cummins in Kew Bulletin, 1898, 80. 

 P. africana^ Presl, Epimel. Bot. 240 ; Klotzsch in Abhandl. Akad. 

 Wissenschaft. Berlin, -1853, 355 (reprint 27) ; Schweinf. Beitr. Fl. 

 Aetfaiop. 193. P. itatalensis, Klotsch, &, P. oethiopica, F^nzl ex Klotzsch 

 in Abhandl. Akad. Wissenschaft. Berlin, 1853, 353 (reprint 26). 

 P. natcuevsis, Garcke in Peters, Beise Mossamb. Bot. 509. P. Leprieuriy 

 Blume, Rumphia, i. 79 ; Klotzsch in Abhandl. Akad. Wissenschaft. 

 Berlin, 1853, 354 (reprint 26). 



Vpper Gulsiea. Senegal, Lelievre, Heudelot (ex Enjler). Ashanti : Assin- 

 Yan-Coomassie, Cummins ! Niger Territory : Nupe ; Lom, Barter, 176 1 River 



