NOTES ON POTAMOGETONS. 371 



Hooker in his A. rosea, have white flowers. But I cannot follow 

 these authors in giving this plant more than varietal rank. Its 

 very large sepals and large oblong buds certainly render it very 

 easy, apart from its geographical separation, to distinguish this 

 from the other white Argemones. But it has the habit and the 

 capsules of the form of A. platijceras characteristic of Southern 

 Mexico, and has petals a little larger than, but of the same shape 

 as, those of A. hiapida. The fact also that the presence of A. ochro- 

 leiica in S. America seems probably due to introduction by Spanish 

 missionaries from Mexico renders it not improbable that this white 

 form of Chili is also an introduction, and that its differences are 

 merely the result of altered environment on what appears to be a 

 species naturally very prone to react to the influences of soil and 

 climate. 



The name chilensis has been given to this variety in order to 

 prevent confusion. As has been said, if it is to be recognised as 

 specifically distinct, its name must be A. rosea Hook., in spite of 

 the probability that the flowers are rarely, if ever, pink. At the 

 same time it cannot as a variety be named A. platyceras var. rosea; 

 that combination of epithets is preoccupied, owing to its use by 

 Coulter to designate a melange of the purple-flowered form of J. 

 platyceras {tijpica) and the pink-flowered form of A. intermedia (ti/pica). 

 To give the name Hunnemannii to the variety might seem like 

 suggesting that the name of Otto and Dietrich should be preferred 

 to that of Hooker ; the one here adopted has consequently been 

 employed. 



A. platyceras type was introduced into European gardens in 

 1827, and flowered that year in Berlin. The Chili plant was 

 introduced in 1833, and was also raised at Berlin; neither has been 

 preserved in European culture. A. hispida and the form of A. 

 platyceras with branched spines, from Texas and New Mexico, have 

 never been introduced. 



NOTES ON POTAMOGETONS. 



By Aethur Bennett, F.L.S. 



In the account of the Indian species of the genus in the Flora 

 of British India (vi. 565-7), Sir J. D. Hooker intended to give only 

 the "broad species," leaving the local forms and subspecies, &c., 

 to be worked out when more material had accumulated. So far as 

 I liave seen, there are fewer number of specimens from India in 

 herbaria than from any other similar space in the world. I make a 

 note here of a few records additional to those in the Flora, as a 

 contribution to some future detailed account of the genus as it 

 occurs within the limits of the work. 



PoTAMOGETON CENSUS L. Himalaya, Kumaon. It occurs in 

 Siberia [Herb. Schreher \), Afghanistan [Herb. Munichl), and Kur- 

 distan, Armenia, Anatolia [Herb. Boissier !). 



2 B 2 



