l'.ll A. BENNETT. POTAMOGETONES OF THE HERBARIUM B0ISS1ER. 287 



herberium sp. is for • the Huachanea .Mis. Pacific '".ist of America. Ily. 

 LemmoD ami wife. 1882 »;a station nui given by D r Morong in hisMono- 

 graph. 



44. P. vaginatus Tmvz. Bull, soc nat. Musc. 27 (1854). For parti- 

 ciilars of tliis species cf. D r Kililinan in Botaniska Notiser 85 f 1 887). 



2 spécimens in the herb, extending its distribution. « Archangel. W. 

 lia us p and « Labrador. Weitz » both with good fruit, and very characte- 

 rislic. Placed under pectinatus by Ledebour in FI. Rossica. 



45. P. filiformis Nolte! Nov. Fl. Holst. 20 (1826). 



Most European authors use the name P. marinus Linn. In the Linnean 

 Herberium the spécimens named marinus are only pectinatus. The plant 

 ligured ly Reichenbach in the Icônes as the marinus All. is the filiformis 

 of Nolte. I hâve seen spécimens of the following, which may be referred 

 with certainly lo Noltes plant; P. setaceum Schum, P. capillaceum Mönch 

 and P. fasciculatis Wolfg which is a small form of. it. 



48. P. Robbinsii Oakes in Ilovey's Mag. 7, p. 180 (1841). 



One of the rarest fruiting species in the genus, it seems to have been 

 gathered only three times in lhat stale. 



A closely allied species apparanlly grows in the great central African 

 Lakes, but the scraps I have seen, are not sufficient to describe, or. make 

 anything definile of. 



49. P. rivularis Gillot Bull. Soc Dauph. t. 4 (1887). 



According to some American botanists this name would have to be 

 sunk, as thcre is a var of rufescens so named by Merl and Koch. Deut. 

 Fl. 1 (1823). In the herberium one sheet of spécimens are not rivularis 

 at all (although sent by D 1 Gillot) but are P. polygonifolius Pour. var. 

 pseudo-fluitans Syme = P. notons L. v. intermedius Mert. and Koch!. 



M. Fryer considers that rivularis is with P. lanceolatus Sm. hybrids of 

 heteroplußlus, eilher with Friesii, or pusillus, cf. J. of Botany337 (1894). 



In another sheet of the herberium I find two spécimens which are 

 without doubt the P. lanceolatus Smith lut the label. I cannot make out 

 its habitat. « Core, Cressidu. In paludibus. 4, 8, 79. A. Letourneux ». It is 

 anyhow an interesling discoverey, as we have for some time considered 

 Smith's plant an endémie British species. 



50. P. Chesemanii Ar. Benn. J. of Bolany 66 (1883). 



In Australia, N. Zealand. and Tasmania this has been variously named as 

 P. notons, P. heterophyllus, and P. gramineus; while M r Kirk calls it 

 P. notons v. australis (Trans. Auckland Inst. 410, 1883). but the species 

 has submerged leaves exceedingly by variable in shape. etc. 



