CHAPTER XIII 



irregular perianths, and five stamens with some traces of pollen. 

 Like many other highly cultivated plants, bananas have lost the 

 power of producing fertile seeds. The banana and the nearly related 

 plantain are the staple food plants in many parts of the tropics; their 

 productiveness in suitable soil is almost incredible; it is said that an 

 acre can produce sixty-six tons of fruit, a fact that helps to explain 

 the indolence of the natives. 



The Orchid family is next to the Compositse in number of species, 

 the estimate being eight thousand. The plants are most interesting 

 in their habits; many of the tropical species are epiphytes in the 

 tops of forest trees, others are saprophytes. The flowers are, of all 

 known species, the most highly specialized with reference to insect 

 visits. But California is very poor in orchids, so that actual observa- 

 tion work with them would be rarely feasible, and they are not of 

 sufficient economical importance to warrant study from books on 

 that pretext; so little space is assigned them here. Orchids 

 have an inferior, one-celled ovary and a six-parted perianth, 

 one part of the perianth, called the lip, being very conspic- 

 uous. Most species have but one fertile anther; the lady-slipper 

 is an exception, having two. The anthers are usually united 

 with the pistil. The lady-slipper, Cypripedium, a genus not 

 rare in the north, admits guests only where they must strike 

 the stigma ; once within the banquet hall, that is, the lower 

 lip, the guest's only exit is via the anthers, and these exits are so 

 narrow that he must smear his shoulders with pollen. The genus 

 Habenaria is the one that compels its guests to carry pollen masses 

 on their eyes; there are several California species of Habenaria bear- 

 ing spikes of small white or greenish white flowers, but they are 

 not abundant and would rarely be noticed ; those I have observed 

 have been fully pollinated. Illustrations of a British Habenaria 

 and a full description of its pollination are given in most botanical 

 text books. The orchid referred to in the Reader as hurling its pol- 

 len masses, is Catasetum saccatum, fully described by Darwin, also 

 by Kerner. Orchids have the smallest of all seeds; so minute are 

 they that, like spores, they may remain suspended in the atmosphere, 

 and so are widely distributed. 



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