228 NOTES ON POTAMOGETONS. 



P. petiolare Presl! DeliciaD Pragenses, 1, p. 151 (1822). P. 

 nutans ft. faliis ellipticus Gussone, Fl. Sic. Synop. .1, p. 206 (1842), 

 non Gaudin, Fl. Helv. 1, p. 467 (1828).— This must be referred to 

 fluitans Auct. P. petiolaris Rafinesque, Med. Rep. 2, hex. 3, p. 409, 



1811, is unknown to me. 



P. Delavayi, sp. nov. — Stem simple, semiterete, striated, 9-12 

 in. high ; lower leaves entirely decayed ; intermediate mostly 

 decayed, linear-lanceolate, 4-5-veined with slender transverse 

 nerves ; upper leaves coriaceous, ovate-lanceolate or nearly lanceo- 

 late, 9-11-veined, with many branched cross-nerves, and chain-like 

 areolation over the whole leaf- surface ; 9-18 lines long, 6 lines 

 broad. Stipules mostly decayed, 9 lines long, blunt, many-nerved. 

 Peduncles slender, 2-3 in. long, nearly equal, but slightly enlarged 

 in the central portion. Spikes 9-11 lines long, dense-flowered. 

 Perianth-leaves mostly decayed, rhombic-orbicular, clawed. Fruit 

 (drupelets) reddish when half-ripe, 2 lines long, ventrally curved to 

 the centre, with 2 basal blunt tubercles, dorsally ^-circular, sharply 

 keeled round to the basal attachment, and extending \ line below 

 it ; secondary (2) keels not prominent. Beak subcentral. Embryo 

 curved to two-thirds of a circle, the upper eud sharply incurved. 



L'Abbe Delavay in Herb. Mus. Paris, No. 4750. Eaux courants 

 des fosses dans la plaine de Ta-li, 20 September, 1888. Province 

 of Yun-nan, China ; ex Franchet. 



Plant with the habit of the narrow-leaved forms of P. polyfjani- 

 folius Pour., but with very different fruit, being three times the size 

 of that species, and in shape quite unlike it. I have seen nothing 

 like this from the central or northern provinces of China, Mongolia, 

 or Manchuria. The Kansu (Potanin !) and Gobi (Potanin !) speci- 

 mens of pohj'jonif alias are the usual form of that plant as it occurs 

 in shallow water. The Abbe Delavay's specimens have evidently 

 grow r n in about 9-12 in. of water, the lower leaves being nearly all 

 decayed, as the specimens were in good fruit. With quite the 

 aspect of the narrow-leaved forms of polt/gonif alius, this plant has 

 the ventral outline of the fruit much like that of P. condylacarpus 

 Fieber. 



P. japonicus Franchet & Savatier, Enumer. Plantae Japonicse, 2, 

 p. 15, 1879, name only. — By the kindness of M. Franchet, I have 

 seen the original specimen of this plant, which, he tells me, was not 

 to hand at the time the Knumeratio was printing, and has never 

 been described as japonicus. It proves to be a narrow-leaved state 

 of P. mucronatus Presl! Epim. Bot. 1849. P. malaina Miq. ! 111. 

 Fl. Ind. Arch. p. 46, 1871. 



P. spathulatus Schrader ap Koch et Ziz. ! Catal. PL Palat. pp. 

 5 & 18 (1814). P. rufescens Schrad. var., Meyer, Ch. Hann. p. 522 

 (1836). P. Kochii F. Schultz ! Arch, de la Fl. d. France et All. 

 p. 61 (1842). P. oblonyo-rufescens Schultz, Flora, No. 15, p. 280 

 (1849). P. riifescenti x ncttans F. Schultz ! Jahrcsb. d. Poll. p. 119 

 (1861). P. alpino-natans F. Schultz! in Jahresb. d. Poll. p. 229 

 (1863). P. alpinw ft. spathulatus Marsson, Fl. Neu. Pom. und 

 Usedom, p. 490 (1869). 



P. spathulatus Nolte, Nov. S. 17, 1826, is a form of P. nutans: 



