228 CLiii. NAiADACE^ (benxett). [iVaios. 



7. N. horrida, A. Br. in Magnus ^ Beitr. Kennt. Gait. Najas, p. vii. 

 a)id 46. Stems long, spreading, with short lateral branches and short 

 internodes, forming at length dense bushy heads. Leaves falcate, 

 with teeth longer than the leaf -widths and a rigid brown spine at the 

 apex ; sheaths broad, rounded-truncate, with 4-6 minute teeth. Male 

 flower subellipsoid. Fruit tapering above. Seed marked with 20 rows 

 of pits. — Rendle in Trans. Linn. Soc. ser. 2, Bot. v. 422 and 443. 

 N. pectinata, Magnus in Aschers. & Schweinf. 111. Fl. Egypte, 145; 

 Durand & Schinz, Gonspect. Fl. Afr. v. 500. 



XTpper Guinea. Senegambia: Lake Guier, Roger; Marsh of Walo, near 

 Keurmbaye, Leprieur. Niger Territory : Nupe ; in a deep lake near Jeba, Barter, 

 1065 ! Caraeroons : Elephant Lake, near Baronibi, Freuss, 452 ! Johann-Albrechts 

 Hohe, Standi, 488 ! 



wrile Iiand. Fazokl, St. Ange, 81 ! Bahr el Ghazal, Schweinf urth, 1137! at 

 the mouth of the River Jur, Schtveinfurth, 1228 ! 



XkKozamb. Slst.' Lake Tanganyika, Hore ! 



Also in North and South Africa. 



8. N. interrupta, K. Schmn. in Engl. Pfl. Ost-Afr. C. 94. Stem 

 slender and wiry ; internodes elongated. Leaves short, with 10-12 

 teeth on the margins ; basal auricle truncate, entire. Female flowers 

 with 2-3 stigmas. Fruit fusiform, dull yellowish. — A. Bennett in 

 Dyer, Fl. Cap. vii. 51 ; Rendle in Trans. Linn. Soc. ser. 2, Bot. v. 423. 



SIEozanib. Dist. German East Africa : in Lake Victoria at Kageyi, Fischer, 

 614! 



Also in South Africa. 



N. australis, Bory, and N. madagascariensis, Rendle, occur in the Mascarene 

 Islands. 



8. CYMODOCEA, Konig ; Benth. et Hook. f. Gen. PI. iii. 1018. 



Flowers axillary, unisexual, or bisexual, in membranous sheaths. 

 Perianth 0. Male flowers : Anthers 2, long, connate, stipitate, extrorse. 

 Female flowers ; Carpels 2, subsessile, ovoid, compressed, 1-ovuled ; 

 style short ; stigmas subulate ; ovule pendulous, orthotropous. Fruit of 

 2 ovoid carpels. Seeds pendulous ; testa thick ; embryo inflexed. — 

 Submerged marine plants, with rigid jointed and creeping rootstocks. 

 Leaves oblong or linear, with stipuiar sheaths. 



Species 5-8 ? Shores of the Indian and Pacific Oceans. 



Leaves not terete. 



Leaves falcate . . . . . . . 1. C. ciliata. 



Leaves straight. 



Leaves broad . . . . . . . 2. C. aerridcda. 



Leaves ^ in. or less wide. 



Leaves 3-nerved . . . . . . 4. C. australis. 



Leaves 7-nerved . . . . . . 5. C. nodosa. 



Leaves 9-13-nerved , . . . . 6. C. rotundata. 



Leaves terete, grooved . . . . . . 3. C. isoetifolia. 



