CXLI. ARACEyE. 817 



Flowers 1-sexuul, monoecious (often dioecious in Arismna). 

 Water or marsh plants ; spadix without a barren 

 appendage. 



Floating stemless herbs ; leaves sessile in a rosette- 

 like tuft 1. PiSTIA. 



Submerged, aquatic or marsh herbs. 



Ovaries in one whorl 2. Cryptocorynb, 



Ovaries spirally arranged 3. Lagknandra. 



Terrestrial tuberous herbs. 



Spadix with a barren terminal appendage ; ovules 

 not parietal. 



Male flowers stipitate ; flowers often dioecious. 4. Aris.ema. 

 Male flowers sessile or nearly so ; flowers 

 always monoecious. 



Flowers and leaves present together. 



Ovules 1-2, basal 5. Typiionium. 



Ovules many, basal and apical 6. TiiBRioPUONtTM. 



Flowers appearing before the leaves. 



Ovules orthotropous; males and 

 females remote ; neuters present 



above the females 7. Sauromatum. 



Ovules anatropous ; males and 



females contiguous ; neuters ... 8. Amorpiiophallus. 

 Spadix without a barren appendage ; ovules many, 

 parietal. 



Female inflorescence adnata to base of spathe ; 



stigma stellate 9. Ariopsis. 



Spadix free from the spathe ; stigma discoid . 10. Remusatia. 

 Flowers hermaphi'odite ; stem scandent ; spathe small 11. Pothos. 



1. PISTIA, Linn. 



A floating gregarious monoecious stoloniferous herb. Leaves sessile in 

 a close spiral, obovate-cuueate, together forming a cup ; veins pai'allel ; 

 stipulary sheaths small, membranous. Spathe small, shortly pedunculate, 

 tubular below, open above ; tube short ; limb ovate, concave, spreading. 

 Spadix adnate to the back of the tube of the spathe, free above. Male 

 INFLOEESCENCB a whorl of a few sessile connate stamens below the apex 

 of the spadix, with a whorl of minute neuters below it ; anther-slits 

 vertical. Female inelobesoence a solitary oblong 1 -celled ovary, 

 obliquely adnate to the spadix for nearly its whole length, the tip free, 

 forming a conical style with a discoid stigma; ovules many, crowded on 

 a parietal placenta, orthotropous. Fruit ovoid ; pericarp thin, bursting 

 irregularly. Seeds many, oblong or obovoid ; testa ultimately rugose; 

 albumen copious, floury ; embryo minute, apical, cuneiform. — Distbib. 

 Species 1, tropical. 



1. Pistia Stratiotes, Linn. Sp. PI. (1753) p. 9fi3. A floating 

 stemless stoloniferous herb with a peculiar muriatic odor ; roots of 

 tufted simple white fibres clothed with fibrillse. Leaves l^—i in. long, 

 variable in breadth, obovate-cuneate, rounded or retuse at the apex, 

 densely and closely pubescent on both surfaces ; nerves few or many, 

 flabellately arranged, converging within the margin, Spathe about | in, 

 long, obliquely campanulate, white, gibbous and closed below, contracted 

 about the middle, dilated and nearly orbicular above. — Distbib. 

 Throughout Lidia and Ceylon and the tropics generally. Fl. B. I, v. 6, 

 p. 497 ; Grab. Cat. p. 200; Dalz. & Gibs. p. 281 ; lioxb. Cor. PI. v. 3 



VOE. II. 3 H 



