156 J. O. HAGSTROM, CRITICAL RESEARCHES ON THE POTAMOGETONS. 



along the whole length up to the middle and above. The interspaces formed by the 

 cross-veins are narrow especially at the middle of the leaf. Margin smooth, base 

 oval to lanceolate, petioles long but shorter than the blades at least below. 



Stem-anatomy: Epidermis with a one-celled pseudo-hypoderma, no or few cortical 

 bundles, O-endodermis and 8 free vascular bundles in the central cylinder (trio-type). 



Though we cannot give the description of the pistils and fruits, the species 

 however is recognizable by the proprieties stated above. I have hesitatingly distribut- 

 ed the above name to the plant concerned, inasmuch as it in many respects seems 

 to answer to the description of P. sumatranus Miq. When nevertheless, according 

 to Miquel's own statement, his species lacks floating leaves and even indications 

 of them, P. hindostanicus cannot possibly be identical with it. Nor with P. indicus, 

 which, like P. sumatr., has the submersed leaves more obtuse, never cuspidate as in 

 P. hindostanicus, cf. Cham., Linn. 1827, 230. See also under P. nodosus! 



Distribution: Asia, Western Himalaya, Kashmir, 56, Schlagintwbit (lib. 

 Stockholm.), »no. of Catalogue 4615 ». Bengal, aug. 68. Leg. S. KuRZ (hb. Haun). 



P. Fraiiclietii Ae. Bennett et Baagoe, in Ar. Bennett, Two new Japanese 

 Potamogetons, The Journ. of Botany, 1907, 234. — Fig. 74. 



end This species seems to be profusely spread in East Asia, together 



with P. perversus Ar. Benn., which is P. digynus Wall, and P. elegans 

 Wall.. They differ from one another in the following way: P. Fran- 

 chetii: Upper leaves broader, 15 — 17-nerved, more obtuse; stigma, see 

 fig. 74, B, C ; fruit with lateral bosses upwards. P. digynus {perversus): 

 Leaves narrower, 13-nerved, more acute, much as the shape of the 

 fig. 77, B; stigma more rounded; fruit without pectoral bosses (fig. 

 74, D). 



Stem-anatomy: epidermis lacking strands and pseudo-hypoderma, 

 no bast- or vascular bundles present in the cortex, endodermis of 

 dZfi'B%m \%al' 0-ce\\s (P. F ranchetH) , or 0-cells with more or less conspicuous -w-cells 

 andp. d;.w«MsWAi,i,. intermixed at intervals (P. die/.). Central cylinder of trio-type in both. 



A, Transverse sec- . „ 7. tt- a 1 ■ i 1 n/io it t^ /-> 



tion of the central Dtstrioution . P. (ttgr. .' Korcau Arclupclago, 1863, coll. R. Oldham 



V '" nrf, endoderals! (hb. Stockholm). Nepalia, Wallich 5177, Singapor, Wall. 5178, — P. 

 ro ^'i'' c'st"''"' Franchetii: Japan, Yokohama, 1862, Maximo vicz (hb. Stockholm), 



and C, Stigma, 

 n above, y*^, ol 

 ?'rancJi. D, Frnit 

 side-view -{, (P. di;/.) 



from above, v°. of Tokio, Hirumushiro and Yokoska, Nippon, Franchet (hb. Haun.). 



p. t'ranch. D, Fin it, ' r-i" ' \ 



P. apicalis n. sp. 



Gaulis ca. 3 dm. v. ultra, teres, crassus (3 mm. in diam.) dense nigripunctatus, 

 nodis annulatus, internodiis mediocribus (summo ca. 6 cm.), simplex v. ramis l:se — 2:8e 

 ordinis prolongatus. Folia (late) lanceolata, corjacea (infima ?) longe petiolata, summa 



