NO. 2 GENTRY : LAND PLANTS 75 



deciduous forest with a multiple dominance of tree species. One of the 

 most conspicuous dominants originally was Spanish cedar, Cedrela^ 

 which oddly enough, although still living upon the islands, has never 

 been collected. The first naturalist to see these forests was Grayson in 

 1865, 1866, 1867, who wrote of them (1871:264). ''The immense 

 cedar (Cedrela odorata) grows in great abundance on this island 

 (Maria Magdalena), not having been disturbed by the wood cutters. 

 This tree makes the finest lumber in the world. It is also common on 

 the coast of tierra caliente. Cleofa, the smallest of the three islands, 

 is also well wooded and has a good little port. All these islands, except 

 Juanito, are covered with a dense forest from the water's edge to the 

 top of the highest hills. The shape of the trees (of which there is a 

 great variety), is generally straight or straighter and taller than upon 

 the main. There is but little thorny underbrush, so characteristic of 

 the tierra caliente." 



Cutting of Cedrela was in progress on Maria Madre at the time 

 of Grayson's visits. Later a penal colony was established on Maria 

 Madre by the Mexican government and disturbance of the native vege- 

 tation has continued. Ferris in 1925 (1927:64) found the area about 

 the penal colony cut over and a weedy aggressive cover advancing, many 

 species of which appeared to be newcomers from the mainland and 

 characteristic of disturbed areas about Mazatlan and San Bias. Little 

 agriculture has been practiced on this island. 



The islands are reputed to have been uninhabited by man until the 

 coming of Europeans, the first of whom to inhabit the islands were 

 buccaneers (cf. Dampier, 1703). If it is true that the Amerindian 

 never inhabited the islands, it is very remarkable indeed, for traces of 

 man indicate that he has over-run almost every square mile of North 

 America at some time during his long residence on this continent. Sixty 

 miles of sea water is a small barrier and although the Spaniards may 

 have found the islands uninhabited, it is still likely that some of the 

 prehistoric peoples who inhabited the adjacent mamland, and some of 

 whom had advanced cultures, must have known of, visited, and even 

 inhabited the Tres Marias for some periods. Maria Magdalena has 

 apparently been only partially disturbed by man, and should this frag- 

 ment of primeval vegetation (never affected by early man) still exist, 

 it would be a singular boone to all students of natural vegetation. 



The known flora of the islands consists of 11 species of ferns and 

 313 spermatophytes. These have been catalogued in 3 separate papers. 

 Rose (1899), Ferris (1925), Eastwood (1929). Over 90% of these 



