Life‐history monographs of Japanese plants. 1: Erythronium japonicum Decne. (Liliaceae)

Abstract

AbstractThe life‐history characteristics and demography of Erythronium japonicum Decne. (Liliaceae) are described here. This is a typical prevernal species of temperate broad‐leaved deciduous forests in the Japanese Islands and adjacent Far East regions, and is one of the representative perennials of Arcto‐Tertiary origin. It flushes in early to late April (in May at higher elevations) on the deciduous forest floor in the lowlands to lower montane zone in Hokkaido, Honshu, Shikoku and Kyushu. Flowering individuals bear a single but showy large purplish‐red flower, blooming downward from the top of the scape. This species is a typical polycarpic perennial and bumblebee‐pollinated outbreeder, with pollen/ovule ratios of 4800–6150, although occasional inbreeding is known in the northern populations of Hokkaido. Yellowish‐brown seeds, 2–3 mm long, with a tiny elaiosome, are susceptible to ant‐dispersal (i.e. myrmecochory). According to our long‐term monitoring study that has continued for the past 25 years, since 1979, its mean life expectancy is extremely long (approximately 40 years).