306 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1936 



in the Tropics. In fact, tliey have come to be symbolic of equatorial 

 regions. The very mention of the word "palms" seems to conjm-e 

 up a vision of bright and sunny lands where the vegetation is luxu- 

 riant, the air warm, balmy, and sweet-scented, and where the spell of 

 enchantment and romance seems ever present. 



There is a well-nigh universal law concerning the distribution 

 of plants which recognizes that a decrease in temperature, going 

 from the Equator toward the Poles, has the same effect upon 

 vegetation as an increase in altitude above sea level. A certain type 

 of vegetation would naturally be able to exist at a higher elevation 

 in the mountains of the Tropics than in those of a temperate zone. 

 The general altitudinal limit of the palm family as a whole is some- 

 what less than 4,000 feet. What an amazing thing it is to find that 

 the Quindio wax palm exceeds this upper limit by about 6,000 

 feet. In fact, there is another species of wax palm growing at the 

 Volcan Chiles, on the boundary line between Colombia and Ecuador, 

 which exceeds even this altitudinal record. Since it averages 40 to 50 

 feet in height, it must be regarded as relatively small in comparison 

 with the Quindio palm, but it is found up to 13,450 feet above sea 

 level; that is, almost 2 miles higher than palms can ordinarily 

 grow.^ The fact that the Quindio wax palm grows at such a high 

 altitude where the mean annual temperature is between 12.5° and 

 18.5° C. (54.5°-65.3° F.) appears to be ample justification for de- 

 scribing it as "the palm of the frigid region par excellence" (Andre, 

 L'Amerique Equinoxiale) . However, except for the species at the 

 Volcan Chiles, the wax palms are not strictly alpine plants, but 

 belong rather to the cool temperate zone.* 



It is also a matter of common observation with regard to the be- 

 havior of woody plants that, when some few representatives of a 

 family are able to maintain themselves beyond the ordinary limits 

 of the majority of the group, they are dwarfed or lacking in vigor — 

 stunted, bushlike vegetation is characteristic of the upper limit of 

 trees the world over. The logical supposition would be that any 

 species of such a tropical family as the palms growing at such ex- 

 traordinary altitudes and enduring the low temperatures just men- 

 tioned would, of necessity, be low, weak, and rather poor specimens, 

 making the most of a bad situation. But the wax palms of the 

 Quindio Pass are the tallest palms in the world. When this species 



* Several smaller palms of other genera are known from fairly high altitudes. 



*It is definitely stated in Chapman, F. M. (The distribution of bird-life in Colombia; 

 a contribution to a biolosical survey of South America, Bull. Amer. Mus. Nat. Hist., vol. 

 36, p. 85, 1917), that the altitudes of the various climatic zones are given as higher than 

 those based on temperature alone. The "tiorra templada" becomes the subtropical and the 

 '■tierra fria", the temperate zone. The wax palms on the eastern slope of the Quindio are 

 mentioned rather surprisingly in the subtropical as well as in the temperate zone in this 

 work (p. 29). 



