Potaniogeton.'] cliii. NAiADACEiE (BENNErr). 223 



Sclnveinfurth refers his 896 to P. pusillum, and also 769 (collected at Acrur in 

 Eritrea), which I have not seen. This plant lias been named P.javanicus Hassk. 

 but its affinities are with P. Hillii, Morong, and P. acutifollus, Link, on the one 

 side, and P. /oZio*?<s, var. californicus, Morong, on the other; more remotely (in 

 foliage only) with P. javanicus, Hassk. A specimen in herb. Boissier. (Yemen, 

 Arabiii, Defiers") may be referred here, but the material is poor. 



10. P. pectmatum, Linn. S;^. PL eel. i. 127. Stem cylindrical or 

 subcompressed, repeatedly branched. Leaves all similar, or the upper 

 sometimes setaceous and 1-nerved, the lower linear and 1-3-nerved- 

 stipules long, adnate to the sheathing petiole, free at the apex. 

 Peduncles short or long, equal in diameter throughout ; spike often 

 interrupted ; upper flowers generally approximate. Fruit large, olive 

 or green, obliquely obovate, slightly compressed, slightly convex on the 

 ventral margin, 3-keeled on the dorsal. — Peters, Reise Mossamb. Bot. 

 511 ; Durand & Schinz, Conspect. Fl. Afr. v. 495. P. marinum, 

 Linn. ? ex Krauss in Flora, 1845, 344. 



Upper Guinea. Gold Coast : Cape Coast Castle, Don ! 



TTile Ziand. Abyssinia : Tigre ; Mai Gouagoua, Quartin-Dillon ! 



]Lower Guinea. Angola : Mossaraedes ; in deep ponds near Aguadas, Welwitsch, 

 250 ! German South-west Africa, ex Durand Sf Schinz. 



IMEozamb. Dist. Portuguese East Africa : Lower Zambesi, in the large lake 

 of Shupanga, Peters ! 



Also in North and South Africa, Socotra and the Mascarene Islands. 



11. P. filiforme, Pers. 'Syn. i. 152. Stem filiform, branched. 

 Leaves all similar, setaceous (or linear-setaceous), 1-nerved, usually 

 much stouter than the peduncles; stipules slender, adnate to the 

 sheathing petiole, free at the apex. Peduncles slender, long, equal in 

 diameter throughout; spike much interrupted, but in a much more 

 regular manner than in P. pectinatuin, as the fruits are usually in whorls. 

 Fruit much smaller than in P. pectinatum, with the beak central and the 

 margins rounded. 



East Tropical Africa. Ruwenzori Expedition : without precise localitv, 

 Scott-Elliot ! 



AVidely distributed in all warm and temperate regioDs. 



12. P. Iiivingstonei, Arth. Bennett. Stem from a slightly creep- 

 ing rhizome, thick at the base, with a strong annulus at the base of 

 the leaves. Leaves densely packed at the base of the stem ; lower 

 leaves resembling those of a Cymodocea in texture, 2J-3 in. long, 

 \—{^ in. broad, thick, half-folded at the base, fiat towards the apex, 

 5-nerved, with numerous waved cross veins, rigid, spreading-erect, and 

 deeply striated; middle leaves less rigid, 1-3-nerved, with the adnate 

 stipules large and entire at the apex ; upper leaves linear-filiform. 

 1-3-nerved. Peduncles short ; spikes short. No fruit seen. 



Mozamb. Hist. British Central Africa : Lake Nyasa ; in the south-western 



