KUNGL. SV. VET. AKADEMIENS HANDLINGAE. BAND 55. N:0 5. 



203 



Though the specimens examined are devoid of spikes and fruits they differ from 

 P. lucens, ziziiformis, and any other allied species so much that they cannot be 

 mistaken for any of them. 



Distribution. South America: Parana, within the 

 mouth-district of Rio Cubatao, gathered Vi 1912 by P. 

 DusBN (hb. Stockholm.). Probably also in Brazil and 

 Argentine. 



P. capeiisis Scheele apud Ar. Bennett, Bemer- 

 kungen iiber die Arten der Gatt. Potamogeton etc., in 

 Annalen Nat. Hofmus. Wien, 1892, 287 (nomen solum). — 

 P. Schweinjurlhii Ar. Bennett, Najadaceae in Thiselton- 

 Dyer, F1. trop. Afr. VIII, 2, 1901, 220? - Fig. 101. 



Ar. Bennett has certainly published the Scheelean 

 name without a closer description, but as he refers to a 

 positive herbal specimen easily accessible, it ought not to 

 be rejected. And if P. Schweinfurlhii should be identic 

 with P. capensis, as Bennett himself supposes (Annuaire 

 du Conserv. etc. Geneve, 1905, 95), a description of P. 

 capensis is herewith also given. I have seen and examined 

 the original specimen of the Bremen museum, thus signed: 

 *Pot. capensis mihi. In Zwartkopsrivier prov. Uitenhage 

 Igt Zeyher Julio » »E Hb. Scheelei, qui schedulam scr. » 

 And the specimens taken by Zeyher and others, preserved 

 in the Swedish museums are identic with them. 



The stem is terete, high-grown and prolongs itself by 

 branches of as far as the fifth rank. Below the primary 

 spike again it seems typically to be unbranched. Possibly 

 it emits long-branches from the base. Submersed leaves 

 short-petioled (10—20 mm) and lanceolate or narrowly 

 lanceolate, 70—80x10-15, or 150—170x15—30 mm, 

 with long, narrow, but obtuse tip, and more or less on the 

 petiole decurrent base, serrulate, 5— 7-nerved, thebroaderand 

 upper ones 12-nerved at the middle, all of lucen s-stvucture. 



Fig. 100. A — C, P. macropJiiflloiiles 

 Haostb. D, p. ziziiformis Haoste. A, 

 stem-leaf, lower half, y. B, Top of a 



In the spike-region the leaves are usually longer petiojed stem-ieaf, f c, Middle pan of a. stem 



. . lilt 1 , If^af, ^Y~ • ■^' Corresponding part of a 



more or less coriaceous, blades lanceolate, stem-ieaf of p. 



ziziif., 



n', h", lateral 



(20—30 mm) 



a little shorter, 60— 80 x 15—18 mm, 13-nerved. Ligides ""■™'- 



brown evidently bicarinate, persistent, 30—40 mm long. Peduncle ca. 5 — 9 cm long, 



even, and not or but little thicker than the interjacent internode. Spike deflorate 



30—40 mm in length. Style thickened above, stigma small, oval or oblong. Fruit 



on the Cape specimens not present. In the form from the Delagoa province it is 4 



mm long by 2,5 mm broad with distinct, somewhat recurved rostrum and strongly 



keeled back; sides convex with faint keels (dry state). 



