24 DR. А. B. RENDLE—BOTANICAL RESULTS 
These specimens show a greater variation as to leaves and nervation than 
the original ones; the broadest are 17-nerved, whereas in the original 
specimens 13 was the largest number of nerves observed. 
Confined to East Tropical Africa. 
Potamogeton javanicus, Hassk. VICTORIA NYANZzA.—Shallow water in river, 
Bukoba, April 20. No. 54 (flower). 
Widely distributed in the warmer parts of the Old World and in Tropical 
and South Africa, but not recorded from Lakes Tanganyika and Nyasa. 
The only other Potamogeton I have seen from Lake Nyasa is P. erispus, 
Linn., collected by Kirk “In Roangiva (Loangiva ?) river." The species 
is widely distributed in all warm and temperate regions. In these great 
masses of water it is surprising that around their margins and bays 
there are so few of this genus. L. Nyasa especially looks like providing 
them, judging by the large map issued for the Railway. 
HYDROCHARIDE Æ. 
Ottellia lancifolia, Rich. Lake Tancanyika.—Swampy pond, Mshale, Feb. 2. 
No. 48. 
Widely distributed in Tropical Africa. 
Boottia scabra, Ridl. LAKE TaNncanyika.—Growing in shallow water, 
mouth of Malagarasi River, Jan. 16. No. 46. 
Previously recorded only from the Central African Nile distriet (Nile and 
Gazelle Rivers). 
Vallisneria spiralis, Linn. Lare Nvasa.— Water-weed growing in about 
4 feet of water; south-eastern arm, near anchorage, June 10. No. 1. 
LAKE TANGANYIKA.—Taken shore-wading, Mtondwe Bay, Aug. 10. 
No. 21. Victoria Nyanza.—Dredged in shallow water in harbour, 
Bukoba, April 25. No. 59. 
Widely distributed in the warm regions of both hemispheres. 
Hydrilla verticillata, Royle, var. brevifolia, Caspary. VICTORIA NYANZA.— 
From shallow water in harbour, Bukoba, April 20. No. 51. 
Vegetative shoots only. 
The species is widely distributed in the warmer parts of the Old World ; 
the variety is recorded from India and East Tropical Africa. 
