Dec. 1893.] BOTANICAL SOCIETY OF EDINBURGH. 45 



water for several months at a time ; and at other times 

 to the opposite extreme of climatic conditions, when it 

 undergoes a prolonged parching and dessication, during 

 which the soil becomes saturated with saline matters. 

 Under such circumstances, the poverty of the ordinary 

 plain flora is still further accentuated. The flora of these 

 inner low-lying parts of the Chaco offering a striking 

 contrast to the mild, semi-tropical luxuriance of the 

 riverain regions along the great fresh-water streams. 



I am indebted to Mr. W. Botting Hemsley, of Kew, for the 

 following note regarding the collection I made. "Amongst 

 the 200 species are a score or so of novelties. As will be 

 seen, they mostly belong to well-known genera ; but the 

 new genus BipIoJxclcha and Quelracliia Moronfjil are 

 specially interesting. The former belongs to the Sapin- 

 daccii^, and is remarkable in having a double cup- 

 shaped disc. Quchrachia belongs to the Anacardiacea', 

 and differs from the only previously known species, in 

 having simple leaves. ]\Iuch yet remains to be done in 

 working out the flora of the sub-tropical part of the 

 Argentine Eepublic. Most of the novelties collected by 

 Tweedie in the region of Buenos Ayres, nearly sixty years 

 ago, still lie undescribed in the Kew Herbarium. Doubt- 

 less many of them were described from other collections 

 by the late Dr. Grisebach in his Symboht- ad Floram 

 Argentinam, published in 1879. In that work he 

 enumerates 2265 species of vascular plants, 31 per cent, 

 of which he regarded as endemic, and 24 per cent, of them 

 were common to Brazil and Paraguay. Many interesting 

 particulars of the flora may be gleaned from the work in 

 question ; and G. Hieronymus has more recently published 

 further novelties in his Icones et Descriptiones Plantarum 

 Argentinarum. 



I desire to thank the Director of Kew for the readiness 

 with which he allowed my collection to be determined in 

 tlie Herbarium of the Royal Gardens, and the officials of 

 the Herbarium I thank for the courtesy they showed me. 

 I have especially to acknowledge the services of, and to 

 thank Mr. IST. E. Brown, who undertook the working 

 up of the collection, and the identification and naming 

 of the species, with the exception of the orchids, the 



