Feb., 1923] SEIFRIZ CAUSES OF GREGARIOUS FLOWERING 99 



at all times of the year. Some few arid localities occur, but they are small 

 and infrequent above 4000 feet. Relatively dry weather may come ccca- 

 sionally at high altitudes, but never a drought above 5000 feet, the elevation 

 at which Chusquea grows. Chusquea abietifolia flowered gregariously in 

 the mountains of Jamaica in 1918 (20). Over an area ten miles in length 

 (investigated by the writer) the trails were, in 1919, lined with dead tangled 

 masses of this climbing bamboo. The two years immediately preceding 

 the flowering of Chusquea were (at Cinchona) unusually moist ones. It is 

 interesting to note that specimens of Chusquea abietifolia sent to Kew, 

 England, in 1884, a year prior to the last previous flowering of the plants 

 (in 1885, the life cycle of Chusquea being thirty-three years), flowered 

 simultaneously with the plants in Jamaica. 



The behavior of Chusquea in Jamaica stands in further opposition to 

 the belief that lack of moisture may cause flowering in bamboos in that it 

 does not support the statement of Brandis that "there are indications, that 

 in dry stony places . . . bamboos flower earlier and more abundantly" 

 (1, p. 662). It was in just such places that the only green living specimens 

 of Chusquea abietifolia were found in the mountains of Jamaica. On an 

 exposed hot and dry spur, sparsely covered by a typically xerophytic 

 vegetation, were growing a quantity of old, green, and thriving specimens 

 of the climbing bamboo. Immediately below this dry spur on which living 

 old plants of Chusquea were growing, there is a moist, cool ravine. Here no 

 adult living specimens were found, but there existed instead the condition 

 prevailing generally throughout the mountains: old plants were dead and 

 growing seedlings were abundant. The old living specimens on the arid 

 spur above were not in fruit. Flowering had not taken place earlier, as 

 Brandis suggests, but, on the contrary, had been delayed. Possibly the 

 climbing bamboo had in this more arid region assumed an altered life cycle. 



In comparing the behavior of the bamboos at Buitenzorg, Java, where 

 droughts are unknown and dry seasons are infrequent, with the behavior of 

 the bamboos in India and Ceylon, where dry seasons of several months 

 come annually and droughts occur frequently, it will be well to consider 

 with the bamboos the equally instructive case of the talipot palm, Corypha 

 umbraculifera, which, like some bamboos, has a long vegetative period at 

 the expiration of which the palm flowers and dies. Ordinarily Corypha 

 umbraculifera does not flower gregariously nor at a fixed age, as do certain 

 bamboos. Consequently, when many specimens of the talipot palm do 

 flower simultaneously, one is likely to suspect the presence of some external 

 factor which has aroused the palms to sexual activity. 



The most remarkable case of simultaneous flowering of plants of which 

 I know is that which recently occurred at Peradeniya, Ceylon. In the 

 annual report for 1918 of the Director of the Royal Botanic Gardens at 

 Peradeniya (4) there appear the following three notes : 



Seven out of the sixteen talipot palms {Corypha umbraculifera) forming the avenue, 



