Flowering phenology and flower morphology of Handroanthus chrysantha

Abstract

To fully understand the flowering biological properties of Handroanthus chrysantha, a famous ornamental tree species in the tropics, the flowering phenology and flower morphology as well as factors influencing it were studied in six areas of Guangdong and Hainan Provinces. Analyses included a variance analysis, multiple comparison analysis and correlation analysis. Results showed that flowering phenology and morphology were significantly different among the six areas (P < 0.05). The plants in Guangdong bloomed earlier with a greater quantity of flowers than those in Hainan, and their flowering stage was on average 10 d longer than those in Hainan. The corolla height of H. chrysantha in Guangdong was longer and the corolla diameter was smaller than those in Hainan. The correlation analysis showed that the first-flowering date was significantly (P < 0.05) and negatively correlated to plant growth (P < 0.01) as well as longitude (P < 0.05), latitude (P < 0.05), and altitude (P < 0.01) of the planting sites, and was significantly and positively correlated (P < 0.05) to efficient accumulated temperature. Flowering duration was significantly (P < 0.05) and positively correlated to longitude (P < 0.01) and latitude (P < 0.05) but significantly (P < 0.05) and negatively correlated to temperature (P < 0.01) and sunshine hours (P < 0.01) of the planting sites. Also, a significant (P < 0.05) and positive correlation for flower quantity and growth trait (P < 0.01) vs. latitude (P < 0.05) and a significant (P < 0.05) and negative correlation for corolla height and temperature (P < 0.05) were observed as well as a significant (P < 0.05) and positive correlation between corolla diameter and sunshine time (P < 0.05).