Some Implications of Precocious Flowering rn Collospermum'

IN HETEROBLASTIC DEVELOPMENT the juvenile and adult phases of a plant have the same genotype but the phenotypes are different, and Cook (1968, p. 97), noting that such phenotypic plasticity has undoubtedly led to a large number of "paper species," finds it rather shocking that so little information on phenotypic modification is. presented in formal taxonom ic work. In the case here described, in the Pacific genus Collospermum (Liliaceae), a single plant can, during its lifetime, display contrasts comparable to some that characterize species or sections in the closely related genus A stelia. In setting up the genus Collospermum, Skottsberg (1934, pp. 72-88) recognized three species in New Zealand. Two, C. bastatum (Col.) Skottsb. and C. microspermnm (Col.) Skottsb., are certainly distinct, though vegetatively very similar. The third species, C. spicatum (Col.) Skottsb., had been described independently by Carse (1926, p. 91) under the name Astelia nana, but Moore (1966, pp . 231232) confirmed Skottsberg 's suspicion that it was based on a "dwarfy" stage or on prematurely flowering seedlings . It is the inflorescence that shows the most striking contrasts at different stages; at the juvenile or "spicatum" stage, plants of the two species are very much alike and very different from their respective adults.