Trillium smallii

Trillium smallii
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Liliales
Family: Melanthiaceae
Genus: Trillium
Species:
T. smallii
Binomial name
Trillium smallii
Maxim.

Trillium smallii is a species of flowering plant in the family Melanthiaceae. It is native to Japan and Sakhalin.[1] It is a rhizomatous geophyte that grows primarily in temperate regions.[1]

Description

Trillium smallii is a glabrous, rhizomatous perennial with erect stems 20–40 cm tall.[2] It has three sessile, depressed rhombic-orbicular leaves, 7–17 cm long and about as wide.[2] The flowers are ascending to horizontal at anthesis and become erect in fruit.[2] The sepals are green or purple-brown, while the petals are usually absent or occasionally 1–3 and small, purple-brown.[2] The fruit is a globose berry about 1–1.2 cm in diameter containing many seeds.[2]

Distribution and habitat

The species is native to southern Sakhalin and northern to north-central Japan.[1] It grows in woodland foothills and flowers from April to May.[2] Populations studied in Hokkaido occur in temperate deciduous forest habitats.[3]

Reproductive biology

Trillium smallii was included in a comparative study of four Japanese Trillium species by Masashi Ohara and Shoichi Kawano.[3] The authors found that, despite differences in ploidy level, the species shared broadly similar reproductive traits.[3] In that study, T. smallii had a mean seed weight of 4.47 mg, the highest reported among the four species examined.[3] Mean seed production was reported as 104.3 and 113.0 seeds per plant in two sampling periods, with estimated seed-setting rates of 48.34% and 52.29%, respectively.[3]

Cytogenetics

Trillium smallii is a hexaploid species with a chromosome number of 2n = 30.[4]

Taxonomy

The species was first published by Carl Maximowicz in 1883.[1] It has long been regarded as a species of hybrid origin in the Japanese botanical literature.[4][3]

A 2006 study by Shosei Kubota, Yoshiaki Kameyama, and Masashi Ohara reexamined relationships among Japanese Trillium species using genetic and chromosomal data.[5]

The study found that T. smallii is most closely related to Trillium apetalon and Trillium camschatcense, rather than to Trillium tschonoskii as suggested by earlier interpretations.[5] Chloroplast DNA evidence also indicated affinity with T. camschatcense.[5]

Based on these results, the authors concluded that T. smallii likely originated through hybridization and represents an allopolyploid derived from Trillium yezoense.[5]

References

  1. ^ a b c d "Trillium smallii Maxim". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 17 March 2026.
  2. ^ a b c d e f "Trillium smallii Maxim". Northeastern Asian Flora. Retrieved 17 March 2026.
  3. ^ a b c d e f Ohara, Masashi; Kawano, Shoichi (1986). "Life history studies on the genus Trillium (Liliaceae). I. Reproductive biology of four Japanese species". Plant Species Biology. 1: 35–45.
  4. ^ a b Uchino, Akinori (1980). "Chromosomal polymorphism in the hexaploid species Trillium smallii Maximowicz". Japanese Journal of Genetics. 55 (2): 109–120.
  5. ^ a b c d Kubota, Shosei; Kameyama, Yoshiaki; Ohara, Masashi (2006). "A reconsideration of relationships among Japanese Trillium species based on karyology and AFLP data". Plant Systematics and Evolution. 261: 129–137. doi:10.1007/s00606-006-0447-4.