Life-history monographs of Japanese plants. 4: Allium victorialis L. ssp. platyphyllum (Makino) Hultén (Alliaceae) Syn. Allium victorialis L. var. platyphyllum Makino; A. latissimum Prokh.

Abstract

The life-history characteristics of Allium victorialis ssp. platyphyllum (Alliaceae), a representative circumboreal element, are described here. This plant is a typical polycarpic perennial of lowland deciduous forests, extending its range to lower subalpine forests. It flashes in early to late April (and in May to early June at higher elevations) on the deciduous forest floor in the lowlands to lower montane zone in Hokkaido and Honshu (north of Nara Prefecture). Flowering individuals bear a single head with numerous whitish or pale purplish flowers on the top of the scape. This plant is a typical insect-pollinated outbreeder, and representative pollinators include small flies (Diptera) and horse flies (Hymenoptera). The number of pollen grains per flower is 4.8–6 × 10⁴, and in the 3-locular ovary only a single ovule is produced for each locule. Pollen/ovule ratios are 1.8–2 × 10⁴. Black ovoid seeds, measuring approximately 3 mm, are dispersed onto the soil layer in late summer. Seed germination occurs in late autumn and germinated seeds overwinter as a radicle. Seedlings with a narrow lanceolate leaf 4–5 cm long begin to appear above ground in early March of the succeeding season. In general, individuals take several years to become sexually mature, but mature individuals with two to three radical leaves will flower continuously and produce seeds.