9G 



LOWKK EOCEXE FLOliAS OF SOUTH EASTEKX XORTII AMERICA. 



ancestor uf the oxisliug Caiuuxiita (ihtusifolia 

 (Lamarck) Do CandoUe, a widely distributed 

 tropical strand jilant. A second species is 

 less commonly represented and not jis certainly 

 identified. The fjenus contains about m dozen 

 existing species of tlie Tropics of bolli liciiii- 

 spheres, but fossil forms have not lieretofore 

 been found. 



The Wilcox forms referred to Leguminosites 

 can not be classified satisfactorily, since they 

 represent pods and leaflets of this alliance 

 whose generic relations are uncertain. This 

 form genus was proposed first by Bowerbanl^ 

 for the p\Titized remains from the Isle of 

 Sheppey (London clay), and two of his species 

 are tentatively identified in the Wilcox. Sub- 

 sequently many species have been described. 

 They range in age from the middle Cretaceous 

 to the Pliocene. The oldest form, in the M- 

 bian of Portugal, is described by Saporta. 

 They are found in tlie Cretaceous of Australia, 

 the Cenomanian of Saxony, tlio Atane and 

 Patoot beds of Greenland, and the Cretaceous 

 formations of the Atlantic Coastal Plain from 

 Marthas Vineyard to Alabama. They are 

 common in the Arctic Eocene and occur also 

 in America, Euro]ie, and Asia. Oligocene 

 records include Europe and the Antarctic Con- 

 tinent; Miocene records are confined to Austra- 

 lia, America, and Europe; and Pliocene records 

 include southern Europe and Japan. 



Th6ugh the foregoing analysis leaves many 

 l^roblems in the history of the Leguminosae un- 

 solved, it shows at least that the Wilcox forms 

 would find a congenial habitat in the present- 

 day American Tropics, in the flora of which they 

 are all i-oprescnted, and that thus early some of 

 the main features of their recent distribution 

 had been determined. 



The most similar fossil display of these forms 

 is found in the Ypresian flora of Alum Bay on 

 the Isle of Wight, wliich unfortunately^ has 

 never boon described or figured, but of wliich 

 Ettingshausen' published an analysis and enum- 

 eration in ISSO. Another very similar display 

 of forms is that described by Engelhardt from 

 the Tertiary of Cerro de Potosi in Bolivia,^ 

 wliose exact age has never been determined, 

 although its resemblance to this part of the 



' Etting-shausen, C. von, Roy. Soc. London Proc, vol. 30, pp. 22S- 

 236, 1880. 



! Engelhardt, Hermann, NaturwLss. Gesell. Isis in Dresden Silz- 

 ungsber. und Abh., 1S8", Abh. 5, pp. 36-38, 7 flgs.; idem, 1894, .\bti. 1, 

 pp. 3-13, pi. 1. 



Wilcox flora suggests the j)ossibility tliat it is 

 Eocene instead of Pliocene, the age wliicli has 

 l)een assumed. This resemblance may, how- 

 ever, simi)ly ])(' a reflection of tlie similarity 

 between tiie L<'guniiii()sa' of tlic eml)avment 

 area in the lower Eocene and those of subse- 

 quent epochs in tlie American Tropics. The 

 small flora desci-il)ed ])y Engelhardt IVom the 

 Tertiary of Ecuador contains 14 species of 

 Leguminosa:>. 



The order Geraniales includes 21 families 

 and more than 10,000 existing species, of 

 wliich nearly half belong to the family Euphor- 

 biacea?. Tlie other large families in the order 

 of their size are the Rutacese, Meliacea?, Mal- 

 pighiacea\ and Polygalacea?, each of which con- 

 tains more tlian 500 existing species. The 

 Geraniacea?, Oxalidacea:', and Burseracere each 

 include more than 300 existing species. The 

 alliance is mainly cyclic in the character of its 

 floral members. The primitive forms are iso- 

 carpic and progress is toward reduction of the 

 number of carpels. The phylogenetic impor- 

 tance of the characters by which the Geraniales 

 as an order is separated from the evidently 

 allied Sapindales is not great and in some 

 respects the order is apparently not a natural 

 one. Six families of Geraniales have been rec- 

 ognized in the Wilcox flora. The first of these, 

 the Rutacefe, consists of about 111 genera and 

 more than 900 existing species, which are widely 

 distributed over the warm temperate and 

 tropical regions. The fruits are capsules, 

 samaras, or drupes, and the leaves, which may 

 be simple or compound, are usually glandular 

 punctate. Though 34 genera and 127 species 

 are confined to America, the family makes its 

 greatest display in the Old World. Africa 

 contains 16 peculiar genera and 19(r species and 

 Australia 28 jjcculiar genera and 1S5 species. 

 In addition to 6 genera and 7 species which are 

 confined to the Asiatic mainland, 19 genera and 

 167 species are distributed from southeastern 

 Asia through Malaysia, some of them as far as 

 New Zealand and Polynesia. The only truly 

 cosmopolitan genus is Fagara, which includes 

 more than 150 existing species and is repre- 

 sented in all tropical countries. The tribe 

 Boroniea', which includes IS genera and 158 

 species, is confined to Australia and New Zea- 

 land; the Diosine.T, which contains 11 genera 

 and 181 species, is confined to South Africa; 

 and the Cuspai-iea^, wliich contains 16 genera 



