128 Materials for a Flora of Hie Malayan Peninsula. 



XVII. NAIADACEAE. 



Aquatic submerged fresh water or marine herbs with slender 

 stems and linear leaves bases sheathing. Flowers uni- or bi-sexual very 

 small green with no perianth or with a small hyaline one. Stamens 

 1 or 2. Carpels 2 or more. 



Naias, L. 



Fresh water or brackish herbs. Stems slender branched. Leaves 

 opposite alternate or whorled linear entire or toothed. Flowers axillary 

 unisexual minute. Male flower with a tubular or inflated entire or 4 

 toothed utricle and a inner one. Stamen 1, adnate to the inner peri- 

 anth tube 1-4 celled. Female flower perianth none or thin and adnate 

 to the carpel. Carpel 1 sessile 1 ovuled. Stigmas 2-4. Ovules basilar 

 erect. Achene oblong, testa thin. Species about 10 whole world. 



Male and female flowers without a spathe 1. N. graminea. 



Male flowers in a spathe. 



Anther unilocular. 



Leaf sheaths truncate rounded ... •■• 2. JV. minor. 



Anther 4 locular. 



Leaf sheaths edges ones lapping large ••• 3. A T . Kingii. 



1. N. graminea, Delile. Descr. Egypt Hist. Nat. II. 282. t. 50. 

 fig. 3. Stems slender 8-9 inches long, but longer in deep water, much 

 branched. Leaves narrowly linear crowded ternate acuminate toothed 

 dark green ^ inch long or more, sheaths truncate toothed, basal auricles 

 toothed, flowers solitary or few together. Males shortly pedicelled 

 nude. Perianth bilobed above. Female flowers 2 to 4 together. 

 Ovary narrow elliptic. Style distinct. Stigmas 2 short. Achene 

 elliptic beaked marked with longitudinal areolae. Kunth. Enum. III. 

 115. Hook. fil. Fl. Brit. Tnd. VI. 569. Rendle. Trans. Linn. Soc. Vol. 

 V. p. 424, pi. XLII. figs. 192-201. N. alagnensis PoW'mi. Fl. Veron. Ill 

 49. A 7 , seminuda Griff. Notul. III. 184, Ic. PI. As. t. 251, fig. 2, t. 2f>:{, 

 254. A. scrristipula Maxim. Bull. Acad. St. Petersb. XII. 72. 



Pahang, Pekan (Ridlev). Province Welleslev, Permatang Bertam 

 (Ridley). 



var. angustifolia Rendl. I.e. p. 427, PL XLII. 202. 



A weak plant with narrower leaves the tips almost setaceous, 

 marginal teeth more conspicuous, fruit smaller. 



Singapore, Garden Lake and ditches often in enormous masses 

 (Ridley 8946, 10316). Distribution of type Europe, Africa, Persia, 

 India, Malay Archipelago, Japan and Australia. Variety distribution 

 Borneo. 



