78 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 13 



cherts with volcanic rocks in many places. No evidence of granite, such 

 as compose the central core of Maria Madre Island was found." 



In 1865-67 Grayson found Maria Madre "unoccupied and covered 

 with a grand forest of fine timber" (1871 :264). Nelson in 1897 found 

 the vegetation similar to that on Maria Madre. He stated that most 

 of the Spanish cedar was gone, but that a large percentage of the origi- 

 nal forest remained intact. Hanna and party "all agreed that the fauna 

 and flora of Maria Madre and Maria Magdalena were almost identi- 

 cal." This is what one would expect of the vegetation, but not of the 

 flora, if Hanna's supposition regarding the geology of the two islands 

 is correct. If Miocene and Pliocene rocks are absent on Magdalena and 

 present on Madre, one would infer that the former is the older, larger 

 area and its flora with a consequent difference in speciation of related 

 groups, which might in part be represented on the younger Maria Madre. 



The known flora of Maria Magdalena consists of only 31 species 

 of vascular plants collected principally by Nelson in 1897 and Mason 

 (35 numbers) in 1925. Francis H. Elmore made a small collection in 

 May of 1939 during the Allan Hancock Pacific voyage. They are 

 enumerated below, Jacquinea aurantiaca being a new addition to the 

 island flora. 



CATALOGUE OF COLLECTIONS 



Polygon AC EAE 



CoccoLOBA ScHiEDEANA Lindau, Bot. Jahrb. Engler 13:187. 1890. 



Magdalena Island, May 9, Elmore lB3y a few plants in boulders 

 and sand along a dry stream at 15 feet elev. 



Apparently along both coasts of Mexico from Sinaloa and Vera Cruz 

 south to Guatemala; type from Papantla, Vera Cruz. 



Theophrastaceae 



Jacquinea aurantiaca Ait., Hort. Kew. ed. 2, 2:6. 1811. 



Magdalena Island, May 9, Elmore IBl, dry rocky partially shaded 

 stream bank, elev. 15 feet. 



From Sinaloa to southern Mexico, Central America, and the West 

 Indies; also on Maria Madre Island. 



Verbenaceae 



Avicennia nitida Jacq., Enum. PL Carib. 25. 1760. 



Magdalena Island, May 9, Elmore 1B2, dry sandy soil of the upper 

 beach. Widespread along the coasts of tropical America. 



