Ludrvigia.] lix. onagrarie^ (oliver). 491 



3. I*. prostrata, Box!?. ; DC. Prod. iii. 59. Diffuse ascending or 

 erect, glabrous ; stem somewhat angular. Leaves lanceolate or linear -^ 

 lanceolate, acuminate, 2-4 in. long, narrowed at base into, petiole of 

 J in. more or less, sometimes minutely setulose-ciliate. Flowers small, 

 %-% in. in diameter ; petals oval or lanceolate. Capsule tetragonous 

 longitudinally grooved, subsessile, |^-1 in. long, l-20th in. in diameter. 

 Seeds about l-30th in. long. — L. diffusa, Ham. in Linn. Trans, xiv. 301. 



Nile Land. Abyssinia, Dillon. (L. abyssinica, A. Kich. Fl. Abyss, i. 274 (ex. 

 descr.) 



Mozamb. Distr. Moramballa, 3000 ft. alt., Dr. Kirk. 



Occurs in India and the Mascareiie group. 



M. De Candolle based his genus Prieurea (P. senegalensis) on a. Ludwigia or Jus- 

 sicea, with flowers frequently 3-merous, collected by Leprieur in Senegambia (Mem. 

 Onagr. 14, t. 2). GuiHemin and Perrottet reduce it to Jussice'a with doubt. I have 

 not seen a specimen. From the figure and description it would appear not improbably 

 a state of Jussicea linifolia. 



4. TRAPA, Linn.; Benth. et Hook. f. Gen. Plant, i. 793. 



Floating herbs. Calyx-limb 4-partite, segments persistent accres- 

 cent, often spinescent. Petals 4, inserted at base of an epigynous 

 disk. Stamens 4. Ovary 2-celled, upper free portion conical, nar- 

 rowed into the style ; stigma capitate ; ovules solitary, pendulous. 

 Fruit turbinate, bony or coriaceous, horned with 2 or 4 of the persistent 

 calyx-teeth, 1-celled, 1-seeded. Cotyledons very unequal, radicle in- 

 curved, penetrating the apex of the fruit on germination. — Leaves 

 dimorphic ; submersed root- like, pinnatipartite with filiform segments ; 

 emersed rosulate rhomboidal dentate on outer margins,, petiolate ; pe- 

 tiole dilated below the lamina. 



A small genus extending eastward through Asia from Central Europe. The farina- 

 ceous seeds are collected as food. 



Nuts 4-cusped. Leaves glabrescent 1. T. natans. 



Nuts 2-homed. Leaves tomentose beneath 2. T. bispinosa. 



1. T. natans, Linn. ; DC. Prod. iii. 63. Rosulate leaves varying 

 usually from 1-2 in. in breadth, base broadly cuneate, outer margins 

 dentate or inciso-dentate, glabrous above, glabrescent or papillose- 

 tomentose on the nerves beneath; petioles glabrescent. Nuts with 

 4 short broad-based cusps or horns ; 1 in. broad more or less. 



Nile Land. Upper Nile, 2° N. lat. Speke and Grant! 

 Also in Central Europe and Temperate Asia. 



2. T. bispinosa, Roxb. ; DC. Prod. iii. 64. Similar to the fore- 

 going. Leaves varying to nearly 3 in. in breadth, generally more or 

 less uniformly appressed-tomentose beneath as are the petioles. Nuts 

 with 2 slender patent lateral horns, the intermediate teeth undeveloped 

 or scarcely prominent, apex shortly apiculate with the persistent style- 

 base. 



Mozamb. Distr. Zambesi, floating down in large quantities by the Shire in flood, 

 and Luabo, Dr. Kirk I 

 Also in India. 



