150 THE JOURNAL OF BOTANY 
these specimens. But the pea sigs runs through all the 
examples, both as to leaf and s 
The leaf-margins of the oe “leaves are Feivvgnssh undulate 
(this may be the result of tension in drying), not ao or 
minute 
argin. A ing 
the top a ag leaf of the Bagjlish Botany a (ed. 
1401) might well have been drawn from one of Mr. Maiden’ s 
specimens. 
Potamogeton semicoloratus, sp. nov.—P. ge awa Ar. 
Benn. in Balfour's Socotra, non Du Croz. Caulis 
simplex. Folia inferiora attenuata geok nervis, hen teed 
oblongo-ovata in petiolo 2 cm. longo, nervus medius reticulato- 
venosus, margine non denticulata. Folia eens (emersa) 
semicoriacea lanceolato-ovata in petiolo 4-6 cm 
Stipule sepius deitrite, 2 ¢ ip ae ‘Pedunen 6 i5 em., 1 dm. 
floating leaves, the Arabian ape are, however, ieee than 
coloratus ay is; on neither of the specimens is there any 
fruit. Mr. Fryer (Pot. Brit. ne p- 25) Sighs doubted my 
reference of a Socotra specimens to colorat 
POTAMOGETON BRASILIENSIS Ar. Benn. in Bs Bot. 1908, 
163. P. Shas L. subsp. brasiliensis Ar. Benn. ex Graebner = 
Das Pflanzenreich. Heft 31, 79 em 7). PB. lucens K. Schum 
Brasil. 111 (1894) 718, t. 119, fi 
Dr. Hagstrom has called my ore to the leaves of this 
plant - Gardner’s n. 2756 from Brazil, saying that the leaves 
t t 
want the se te margins of the lucens forms. This is so, and 
the plant must stand as a distinct species. 
e plant must be rare, as I know of only three specimens in 
our herbaria in Britain, and there is no record of any of the 
other Brazilian species being gathered in the Province of Piauhy, 
yet this is a settled province and a small one, extending from the 
sea coast at Cantagallo south to the Sierra de Piauhy in 10°S 
lat. Of course in such a vast country as Brazil, a so little 
searched (comparatively), it may be much air e frequen 
Potamogeton dissimilis, sp. nov.—Caulis ae filiformis 
c. 1 mm. crassus) dm. longus, internodis 4-10 cm.-6 cm., 
foliis seepe fasciculatis. Folia dm. longa, ad 3 m 
lata, ad apicem rotundata-obtusa vel angustata, mucronata, 
5-nervia ad folium basin, multis nervis recta iter sig masters 
tipule adnate ad 5 em. longer, apica oe ad 2 m ongo, 
obtuso, viridulo. Pedunculus 2-5 em. longus, filiformis. Spice 
1-2 em. longe, pauciflore (8-10) proxime vel fababripaae Fructus 
non visus. 
