A taxonomic study of the genus Pseudostellaria in Korea

The genus Pseudostellaria (Caryophyllaceae) in Korea was investigated in order to clarify the taxonomic positions and scientific names among the species in this genus based on morphological characteristics. P. × bohyeonsanensis and P. × seoraksanensis share several characteristics (trichome on the sepal margin and midvein, five petals, and stem reclining to the ground after flowering) with P. davidii. P. × bohyeonsanensis, resulting from natural hybridization of P. davidii and P. okamotoi var. longipedicellata, has sterile fruit and a long pedicel (2.2–6.0 cm). P. × seoraksanensis, a natural hybrid of P. davidii and P. palibiniana var. palibiniana, has sterile fruit and a short pedicel (1.1–1.8 cm). P. okamotoi var. longipedicellata shares several characteristics (long pedicels of chasmogamic flowers that elongate to the ground when bearing fruit and cleistogamic flowers with a long pedicel) with the related taxa P. okamotoi var. okamotoi. P. okamotoi var. longipedicellata has slender root tubers, glabrous pedicels, and 5–9 petals. P. palibiniana var. gageodoensis is described from Gageodo Island. It is similar to P. palibiniana var. palibiniana having chasmogamic flowers at the stem terminal, 5–7 petals, and a short pedicel, but P. palibiniana var. gageodoensis is distinguished by 1–2 rows of trichomes on the pedicel, a large sepal size, a large petal size, and a branched stem at its base. P. × biseulsanensis, from a natural hybrid of P. heterophylla and P. okamotoi var. longipedicellata, has a solitary aerial stem, a chasmogamic flower at the stem terminal, a shallow marginate or bitten petal apex, one row of trichomes on the pedicel, and sterile fruit. P. × segeolsanensis, from a natural hybrid of P. palibiniana var. palibiniana and P. okamotoi var. okamotoi, is described from Segeolsan Mt. It has numerous aerial stems, a chasmogamic flower at the stem terminal, 1–2 rows of trichomes on the pedicel, and fertile fruit. Consequently, the genus Pseudostellaria in Korea has been classified into eight species, four hybrids, two varieties, and five forms.