Vol.45 TORREYA December 1945 



The Behavior of the Flowers of the Aguacatillo (Persea caerulea) 



Alexander F. Skutch 



In 1929, stimulated by the work of Stout (1927) on the flower behavior 

 of the avocado in subtropical Florida and California, I made brief observations 

 on the anthesis of avocado trees growing in tropical Panama (Skutch, 1932). 

 During subsequent years, while collecting plants in Central and South America, 

 I have tried to find other species of the same family which exhibit a similarly 

 complex mechanism for favoring cross-pollination. The Lauraceae is well 

 represented in the forests of tropical America, and many species were col- 

 lected ; but most were tall trees that bore their flowers at such heights that 

 it was not practicable to make continuous observations upon them. 



So far as has been determined, no species of the great genus Nectandra 

 exhibits the double anthesis of the avocado. On the other hand, it seems 

 probable that the flowers of the wild avocado or yas {Persea Schiedeana) 

 would behave more or less like those of its congener ; but the only flowering 

 trees of this species that I have seen were forest giants whose inflorescences 

 were displayed far beyond reach. Aside from the avocado, the only member 

 of the laurel family in whose flowers I have actually observed double anthesis 

 is the aguacatillo (Persea caerulea). 



The aguacatillo (Fig. 1) is a small or medium-sized tree with a full, 

 shapely, rounded crown of glossy, ovate or elliptical leaves. The tallest speci- 

 mens I have seen were about seventy feet high. It is a tree of the clearings, 

 often growing in pastures, and in Costa Rica is abundant between two thou- 

 sand and five thousand feet above sea-level, both on the Central Plateau and 

 in the basin of El General. I have never found it in heavy forest. In El General 

 it generally sheds its foliage at the height of the dry season in February. The 

 dying leaves turn a fairly vivid red and make a bright display of autumnal 

 colors, rare among tropical trees. Because they put forth their new foliage 

 while shedding the old, however, there are usually far more green than red 

 leaves upon the aguacatillo trees. They are, therefore, never quite so colorful 

 as many northern trees in autumn. The name "aguacatillo," applied to this 

 tree by the Costa Rican country people, is the diminutive of "aguacate" 

 (avocado). The fruit measures about 9 mm. in diameter and contains a single 

 seed, like a miniature avocado seed, surrounded by a very thin, green pericarp. 

 No larger than a pea, the fruit is far smaller than any true avocado and is 

 eaten by birds. The glossy, leaden-gray drupes ripen in June. 



When they have shed, in their colorful manner, all or practically all of 

 their old foliage and have put forth a fresh set of glossy leaves of a bright, 

 vivid green, the aguacatillo trees begin to flower, usually in March in El 



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