The Flora of Lower Siam. 



By H. N. Eidley, m.a., f.e.s. 



The political kingdom of Siam may be said to consist of 

 two parts, the larger or Siam proper, Long. 100-105," Lat. 

 12-15, lying North and West of Cambodia, and South of Laos 

 and the Shan States, the smaller or Lower Siam consisting 

 of a Peninsula Lat. 12-6 connecting Burmah with the Malay 

 Peninsula. The upper part of this Peninsula is the province 

 of Tenasserim which runs down the West coast to Victoria 

 point. This country has been botanically explored by 

 Wallich, Griffith and later botanists as has the Mergui 

 archipelago lying to the West, and the flora is incorporated 

 in the flora of British India ; of the Southern and Siamese 

 portion from the isthmus of Kra southwards comparatively 

 little has been known till recently. The Flora is quite 

 distinct from that of the Malay Peninsula and it was to find 

 the boundary line between these two floras that I visited 

 Alor Star, Perlis and Setul in March 1910, and made a good 

 collection of plants. I found that the boundary line lay about 

 Alor Star, and propose in this paper to put together an 

 account of the plants of this Peninsula from this point as 

 far North as Eenong. Some years ago I made an expedition 

 to Kedah Peak expecting to find there the Siamese flora 

 represented but the flora was strictly Malayan. This mountain, 

 and I am informed Gunong Perak also, are granite, and the 

 termination of the granite chain of the Malay Peninsula. 

 Gunong Perak has not been visited by any botanists as yet, 

 but it will probably be found to bear also a -Malayan flora. 

 At Alor Star there is a complete change of flora, accompanied 

 by the replacing of the granite by sandstone rocks, and a 

 change of limestone hills ending at Perlis, except for a few 

 scattered ; blocks such as Gunong Geriang, near Alor Star. 

 These sandstone and limestone hills and ridges rise out of 



Jour. S. B. R. A. Soc, \'o. 59, I9H- 



