The phenology and related aspects of alocasia brisbanensis (Araceae) at Indooroopilly, Queensland

Abstract

In a continuation of the biological studies on the indigenous aroid, Alocasia brisbanensis (F.M.Bailey) Domin, the date of the commencement and the extènt of the flowering season were recorded at Indooroopilly. This involved tagging at anthesis each of 1948 inflorescences on 716 plants during 5 seasons. Flowering began usually during mid-September, reached a peak about late October to late November, and ceased about mid-December. During anthesis, the spathal chamber remained open for 2 to 4+ days with 93.1% open for 3 to 4+ days. There were up to 8 inflorescences per plant, with up to 9 per plant in 2 seasons, while the mean number of inflorescences was 2.7 ± 1.8 per plant. Maturation of the infructescences, recorded during 3 seasons, occurred mainly between early January to early March with a peak from mid-January to mid-February. Inflorescences which came into anthesis early in the season had a mean of 102.7 days to infructescence maturity, whereas those produced later in the season had a mean of 86.3 days. Analysis of flowering and fruiting records at Indooroopilly and other sites in Queensland and elsewhere in Australia suggests that the onset of flowering is delayed with increasing latitude and altitude due to a decrease in temperature.