Naias.] Naiadece. 375 



4. NAIAS, Z. 



Submerged fresh or brackish water plants, stem rigid, 



stout or slender, dichotomously branching ; 1. opp., alt, or 



whorled, linear, toothed ; fl. axillary, minute, moncEcious or 



dioecious; malefl. : — a single 1-4-celled anth,, adnate to the 



inner surface of a hyaline, tubular spathe, which is again 



enclosed in a more herbaceous outer spathe, pollen oblong; 



fem. fl. : — a sessile, naked, ovoid, i-ovuled carpel, style short, 



stigmas 2-4, terminal, subulate, ovule basilar, erect, ana- 



tropous ; fr. an oblong achene ; seed oval, testa thin or 



coriaceous, embryo straight. — Sp. 23; 4 in FL B. Ind. 



The Ceylon specimens of this genus are not sufficient for full descrip- 

 tion. The species should be described from fresh flg. and frg. plants. 



Stem and branches with toothed wings . . . i. N. major. 

 Stem and branches naked. 



Anth. 6-celled 2. N. graminea. 



Anth. I -celled 3. N. MINOR. 



1. N. major, All. Fl. Pedemont ii. 221 (1785). 

 Trim, in Journ. Bot. xxvii. 167. 



Fl. B. Ind. vi. 569. Griff. Ic. PI. As. iii. t. 251, f. i {N. fucoides). 



Stem rather stout, terete, brown, fragile, and branches 

 armed with an interrupted, membranous, green, toothed wing, 

 or teeth; 1. |-ij in., subternately whorled, linear, coarsely 

 almost pinnatifidly toothed, teeth 4-8 on each margin and a 

 few dorsal, triangular, base hardly dilated into a sheath with 

 rounded entire sides ; fl. dicecious, outer spathe of male 

 oblong, 2-3-toothed ; anth. 4-ceIled ; achene jV-^ in., stigmas 

 2-3 ; seed ovoid, testa crustaceous, obsoletely rugose. 



Brackish shallow lagoons ; apparently very rare. Near Kalmunai, 

 1885 (Nevill). Fl. May. 



Throughout the warmer parts of the Old World. 



2. N. gro-minea, Del. Fl. Es^ypt. 282 (1812). 



Trim. Syst. Cat. Ceyl. 90, and in Journ. Bot. xxvii. 168. C. P. 3887. 

 Fl. B. Ind. vi. 569. (?) Griff. Ic. PI. As. iii. tt. 253, 254 {N. seminuda). 



Stem 1-2 ft, slender, smooth ; 1. |-i in., opp., ternately 

 whorled or fascicled, linear or subulate, acuminate, flaccid, 

 acutely minutely many-toothed, flat, translucent, auricles of 

 sheath erect, lanceolate, toothed on both margins ; fl, monoeci- 

 ous, fascicled ; anth. 4-celled ; stigmas 2. 



Still water in the low country, especially in the shallow lagoons near 

 the coast ; rather common. Trincomalie (Glennie) ; Matalan, N. Prov. 

 (Nevill) ; Batticaloa (Nevill) ; Kurunegala ; Peradeniya. Fl. Feb.-June. 



Warm regions of the Old World generally. 



The specimens are insufficient for a satisfactory determination of this 



