NA TURE 



17 



THURSDAY, NOVEMBER 29, 1877 



FLORA OF MAURITIUS AND SEYCHELLES 



Flora of Mauritius and the Seychelles : a Description of 

 the Flowering Plants and Fer7is of those Islands. By J. 

 G. Baker, F.L.S. (London : L. Reeve and Co., 1877.) 



THIS compact volume of nearly 6go pages, adds 

 another to the already long list of colonial floras 

 prepared at Kew and issued under the authority and at 

 the expense of the Colonial Government. It is arranged 

 on the same plan as the other floras, many of them so 

 well known, giving first, some general remarks on the 

 physical geography and botany of the islands, and then that 

 admirable outline of elementary botany prepared by Mr. 

 Bentham, and which contains every definition necessary 

 in descriptive botany, thus enabling the student to follow 

 the technical descriptions given in the " Flora " itself. 

 The work is almost entirely from the pen of Mr. J, G. 

 Baker (the Orchids being by Mr. Le Marchant Moore, 

 and the Palms and Pandani by Dr. I. B. Balfour), and is 

 only another example of the indomitable industry so 

 characteristic of Mr. Baker. The materials at the disposal 

 of the author have been ample, and probably there is but 

 little left to discover in Mauritius, the Seychelles, and 

 Rodriguez, although many forms have not as yet been 

 fully determined owing to the want of perfect specimens. 

 Hence it is desirable that naturalists visiting the islands 

 should endeavour to complete our knowledge of these 

 imperfectly known plants. The smaller dependencies of 

 Mauritius have not been explored botanically, hence 

 there is probably a rich field for the investigator of these 

 numerous islands. It is, moreover, all the more desirable 

 to have these islands explored as the native flora of the 

 islands already known has been completely altered by the 

 introduction of cultivated plants and weeds as well as by 

 the destruction of the native forests. Thus it is probable 

 that in some of the undisturbed islands a rich native flora 

 may be met with, or that some of the forms either rare or 

 extinct on other islands, may yet be comparatively 

 abundant. 



Mauritius is about 39 miles by 35, and has an area of 

 700 square miles, or a little smaller than the County of 

 Surrey. It is situated at a distance of about 500 miles 

 from Madagascar and 100 miles from Bourbon, and is 

 just within the Tropic of Capricorn. The northern part 

 of the island is a low plain covered with sugar plantations. 

 In the centre is an elevated plateau rising to about 1,500 

 feet above the sea- level, the great mass of the rocks being 

 entrely volcanic. Outside the central plateau, and within 

 a short distance of the sea, rise the three principal moun- 

 tain ranges, the highest portions being from 1,900 to 2,900 

 feet in height. There are two small lakes in the central 

 plateau, the Grand Bassin and the Mare aux Vacoas. 

 There are six rivers, about ten to twelve miles in length, 

 and numerous small rivulets. The climate is warm, and 

 at Poit Louis the mean annual temperature is 78° F. As 

 a result, the vegetation has a decidedly tropical character. 

 There are however, a few south temperate plants present, 

 and also a number of the widely-spread temperate forms, as 

 Nephrodt2imfilix-mas^ Cardamine hirsuta, Juncus effusus, 

 Convolvulus arvensis, Plantago majory and P. lanceolata. 

 Vol. XVII.— No. 422 



Sugar is extensively cultivated in Mauritius. The increase 

 in the cultivation "of sugar has led to the destruction of 

 the forests, which at one time covered the island to the 

 water's edge. As a result of the destruction of the forests, 

 the indigenous flora has almost become destroyed. The 

 orchids, ferns, pandani, and the shade-loving plants, and 

 the curious endemic trees and shrubs have, within 100 

 years, been either entirely exterminated, or else have 

 become exceedingly rare and local. The native vegeta- 

 tion thus partly exterminated has been replaced by a 

 number of introduced trees, shrubs, and weeds, to an 

 extent only exceeded by the destruction of the indigenous 

 flora of St. Helena. There seem to be about 269 intro- 

 duced plants in Mauritius, and 869 undoubted native 

 species, making a total flora of about 1,138. 



The Seychelles are situated 900 miles nonh-east of 

 Mauritius, in 3°-6° south latitude, and consist of a group 

 of about thirty islands, most of them of very small size. 

 The islands are entirely granitic. The largest of the 

 group, Mahd, has an area of 30^000 acres ; the best culti- 

 tivated and most populous is La Digue, with an area of 

 2,000 acres. The mountains range from about 1,500 to 

 3,000 feet in height. The seasons are similar to those of 

 Mauritius. Cotton was at onetime extensively cultivated, 

 and the aboriginal forests were destroyed to make room 

 for cotton plantations. Now cotton is hardly cultivated, 

 the chief exports from the island being cocoa-nut oil and 

 fibre. The vegetation is wholly tropical ; the few tempe- 

 rate species found in Mauritius being absent from the 

 Seychelles. The number of flowering plants and ferns 

 from these islands is 338. Five genera of palms and one 

 genus of Ternstroemiacese are endemic. The endemic 

 palms are mostly well known, and belong to the genera 

 Deckenia, Nephrosperma, Roscheria, Verschaffeltia, 

 Lodoicea, and Stevensonia, The total number of 

 endemic species is sixty. The rest of the flora consists 

 chiefly (250) of widely distributed tropical plants, and be- 

 tween twenty and thirty are of characteristic Mascarene 

 types. The flora was expected to have been much richer 

 in endemic forms from the isolated position and peculiar 

 geological construction of the islands than^it has proved 

 to be after the most careful examination. 



Rodriguez is situated 300 miles to the north and east of 

 Mauritius, and is an island about eleven miles by five, with 

 the hills in the interior reaching an elevation of little over 

 1,000 feet. The rock is entirely volcanic, and the climate 

 similar to that of Mauritius. The flora must have 

 undergone great changes, as the earliest records of the 

 island state that it was entirely wooded. The plants of 

 the island number about 202 wild flowering plants and 

 ferns, nearly all collected, ^by that rising young botanist, 

 Dr. I. B, Balfour, one of the staff of the Transit of Venus 

 Expedition to Rodriguez. Of the 202 wild species, thirty- 

 six are peculiar to the island j and there are three 

 endemic monotypic genera, one Mathurina having been 

 discovered and described by Dr. I, B, Balfour. 



The total number of species as given by Baker may be 

 thus summarised : — There are 1,058 native species in the 

 " Flora," 869 natives of Mauritius, 338 natives of Sey- 

 chelles, and 202 native in Rodriguez ; 269 are naturalised 

 in these islands, thus giving a total number of 1,327 

 species included in the " Flora of Mauritius and the 

 Seychelles." The distribution of the species in the flora 



