DISTRIBUTION. 217 



with two air-canals in the petiole and one root per leaf; the figure gives it 

 a certain resemblance to N. mexicana. Nymphaeites palaeopygmaeus Sap. 

 had also two main air-canals and three to five roots, but Saporta consid- 

 ered it near to Anoectomeria. Nymphaeites webcri Casp. ( = Nympliaca 

 Arcthusae Weber, 1850, not of Brongn., 1822 ; = Carpolitcs granulates 

 Weber) and Nymphaeites ludwigii Casp. (1856) probably are akin to the 

 Nymphaea calophylla group. Nymphaea dubia Wat. was shown by Bureau 

 (1888) to be really a Nuphar ; and of Nymphaea blandusiae Ung., doliolum 

 Ludw., doris Heer, and Nymphaeites saxonica Fried, we have learned 

 nothing but the names. 



During the warmer portions of the Tertiary the genus Nymphaea 

 extended far into the arctic zone. N. arctica Heer (1869) of Spitzbergen 

 has left quite complete remains. Its rhizome and leaf suggest N. alba ; 

 there were four main canals in the petiole and a number of evident ones 

 surrounding these. The sepals were elliptic, with slender longitudinal 

 veins. There were about 1 2 carpels, and the fruit was much enlarged 

 below the narrow (6 mm. wide) depressed stigma. It certainly belongs to 

 the Castalia group. Nymphaeites tliulensis Heer was found in the same 

 locality, but poorly preserved. In Grinnell Land also Captain Feilden of 

 the English North Polar Expedition found N. arctica (Heer, 1878 a, c] 

 and an allied fragment named Nymphaeites tetter (Heer, 1878 b}. 



From such forms and such localities doubtless all of the Castalias of 

 Europe and America are alike derived. The genus Nymphaea probably 

 originated in western Europe and spread over the Arctic continent. Very 

 early, though fossil evidence does not indicate when, the syncarpous and 

 apocarpous groups were separated. Of the latter, A r . gigantca, from its 

 absence of styles and restricted distribution in the ancient Australian 

 flora, is most primitive. The lowest Brachyceras types are the short- 

 styled and pale-flowered American forms N. clegans and flavo-vireiis, from 

 which we ascend through N. caerulea and stellata to zanzibariensis, the most 

 gorgeously colored, largest-flowered, longest-styled species of the group, 

 and also the farthest removed from the original center of distribution. 



Among Syncarpiae, the Castalia group is most primitive, and of these 

 we have already mentioned N. mexicana as the lowest, with N. tetragona 

 as a close second. In Europe the Lotos section was segregated off from 

 these at a very earl)' date, probably through forms somewhat similar to 

 N. calophylla and gypsorum. N. lotus is nearest to the parent stock, and 

 N. rubra most removed. N. tJiermalis remains to testify to the minimum 

 age of the type. N. Candida has kept near home and has probably 



