Objective To explore the flowering biological characteristics of Pseudosasa viridula S. L. Chen et G. Y. Sheng.

Method Field observation and optical anatomy were used to study the flowering biological characteristics of flowering forest facies, flowering dynamics, flower organ structure, fruiting condition and so on.

Result Pseudosasa viridula is a kind of continuous flowering bamboo species, and its flowering period is from January to May of each year, and the period of full bloom is from March 1 to April 15. The types of flowering are complex and diverse, which are mainly divided into three types: old bamboo flowering type, new bamboo flowering type and non-flowering type. Under natural conditions, the fruiting rate is very low, only 0.12%, and the regeneration of post-flower bamboo forest conducts mainly through asexual reproduction. The whole inflorescence consists of 3 or 4 spikelets, with 8 - 10 florets on each spikelet. Each floret contains 1 lemma, 1 palea, 3 lodicules, stamens mostly 3 (very few are 6), 1 pistil and 3 plumose stigmas. The flowering order of the whole inflorescence is top-down, while the flowering order of florets on the same spikelet was bottom-up, so the inflorescence of Pseudosasa viridula belongs to the mixed inflorescence. The floret is monochogamy and the fruit is caryopsis.

Conclusion This study provides a theoretical reference for sexual breeding and cross breeding of bamboo, as well as a certain basis for the study of low seed setting rate and cross breeding of Pseudosasa viridula.