K.UNGL. SV. VET. AKADEMIENS HANDLINGAR. 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 

 m istaken for any of them. 



Distribution. South America: Parand, within the 

 mouth-district of Rio Cubatäo, gathered ! /i 1912 by P. 

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

 Argentine. 



P. capeiisis Scheele apud Ar. Bennett, Bern er- 

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

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

 P. Schweinjurlhii Ar. Bennett, Najadacese in Thiselton- 

 Dyer, Fl. 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. Schiveinfurthii should be identic 

 with P. capensis, as Bennett himself supposes (Annuaire 

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

 capensis is herevvith also given. I have seen and examined 

 the original specimen of the Bremen museum, thus signed: 

 »Pot. capensis mihi. In Zwartkopsrivier prov. Uitenhage 

 lgt Zeyher Julio» »E Hb. Scheelei, qui schedulam ser.» 

 And the specimens taken by Zeyher and others, preserved 

 in the Svvedish 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 

 petioledecurrentbase,serrulate,5— 7-nerved, thebroaderand pig 100 ^_ c p macr ophyiioides 

 upper ones 12-nerved at the middle, all of ?«cens-structure. IlAi '' ru A p - ^uformis hagstk. a, 



Stem-leaf, lower half, \. B, Top of a 



In the spike-region the leaves are usually longer petioled stem-ieaf, \. c, MicMie part of a stem 



i c\r\ nr\ \ i • 1111 i leaf, 2 y 2 . D, CorrespondinR part of a 



(20 — 30 mm) more or less conaceous, blades lanceolate, stem-ieaf of p. ziziif., f, »', n«, uterai 

 a little shorter, 60—80x15—18 mm, 13-nerved. Ligules nerves ' 



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). 



