The genus Pseudostellaria (Caryophyllaceae) in Korea was investigated in order to clarify their taxonomic position and scientific name among species based on morphological characteristics. Pseudostellaria sylvatica (Maxim.) Pax can be distinguished fr...
The genus Pseudostellaria (Caryophyllaceae) in Korea was investigated in order to clarify their taxonomic position and scientific name among species based on morphological characteristics. Pseudostellaria sylvatica (Maxim.) Pax can be distinguished from the others by its subulate or linear-lanceolate leaf blades and five petals with deep marginate apex. P. japonica (Korshinsky) Pax has leaves pubescent on the margin, surface and on the midrib beneath, and five petals with swallow marginate apex. P. baekdusanensis M. Kim, described firstly from Mt. Baekdu, was also discovered in the Yongneup wetland. P. baekdusanensis found in Mt. Baekdu was distinguished from those in Yongneup having cleistogamous flowers, although they shares the characteristics of small plant size, pubescent margin and base of leaf, and five petals with deeply marginate apex.
P. davidii (Franchet) Pax, P. davidii (Franch.) Pax x P. okamotoi var. longipedicellata (S. Lee, K.I. Heo & S.C. Kim) H. Jo, and P. x seoraksanensis M. Kim & H. Jo share the following characteristics: trichome on sepal margin and midvein, five petals, and stem recline to the ground after flowering. But P. davidii bears fertile fruit. P. davidii x P. okamotoi var. longipedicellata, resulting from a natural hybridization of P. davidii and P. okamotoi var. longipedicellata (S. Lee, K.I. Heo & S.C. Kim) H. Jo, has sterile fruit and a long pedicel (2.2-6.0 cm). P. x seoraksanensis, a natural hybrid of P. davidii and P. palibiniana (Takeda) Ohwi has sterile fruit and a short pedicel (1.1-1.8 cm). P. bulbosa (Nakai) Nakai with sub-globose root tubers was synomized to related taxa P. davidii by its overlapping root tuber shapes. P. okamotoi Ohwi is distributed in Mt. Jiri, Mt. Deogyu, Mt. Gaya, and Mt. Baekun (Jeonnam). It has five petals, 1-2 rows of trichomes on its pedicel, and long pedicel of chasmogamic flowers that elongate to the ground when bearing fruit. P. okamotoi var. longipedicellata shares several characteristics (long pedicel of chasmogamic flowers that elongate to the ground when bearing fruit and cleistogamic flowers with a long pedicel) with related taxa P. okamotoi. P. okamotoi var. longipedicellata has slender root tubers, glabrous pedicel, and 5-9 petals. P. okamotoi var. longipedicellata for. daegwallyeongensis H. Jo is described from Daegwallyeong. It has leaves pubescent on the upper surface, margins, and beneath the midrib. P. okamotoi var. longipedicellata for. palgongmolongiana H. Jo is described from Mt. Palgong. This taxa related to P. okamotoi var. longipedicellata is characterised by short style, short stamen, and spiral style. P. palibiniana (Takeda) Ohwi and P. okamotoi var. longipedicellata show similarity in their appearance, but P. palibiniana is easily distinguished by its short pedicel of chasmogamic and cleistogamic flowers. P. palibiniana for. hallasanensis H. Jo is described from Mt. Halla. It has leaves pubescent on the upper surface, margins, and beneath the midrib. P. monantha Ohwi and P. coreana (Nakai) Ohwi are conspecific to P. palibiniana. P. palibiniana var. gageodoensis M. Kim & H. Jo is described from Gageo island. It is similar with P. 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, large sepal size, large petal size, and branched stem at its base. P. setulosa Ohwi has rhizome with root tubers, six petals, and leaves pubescent on margins and beneath the midrib. P. heterophylla (Miquel) Pax has pubescent pedicels, five petals, 1-many chasmogamic flowers at the end of the stem, and a solitary aerial stem. P. heterophylla for. puberula (Ohwi) Mizushima has leaves pubescent on upper surface, margins, and beneath the midrib. P. heterophylla (Miq.) Pax x P. okamotoi var. longipedicellata (S. Lee, K.I. Heo & S.C. Kim) H. Jo from natural hybrid of P. heterophylla and P. okamotoi var. longipedicellata has a solitary aerial stem, a chasmogamic flower at the stem terminal, shallow marginate or bitten petal apex, 1 row of trichomes on the pedicel, and sterile fruit. P. x segeolsanensis M. Kim & H. Jo from natural hybrid of P. palibiniana and P. okamotoi is described from Mt. Segeol. 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.
An ecological study was conducted to identify the natural environment, as well as to plan conservation strategies for the Korean endemic Pseudostellaria species. Pseudostellaria species were distributed along slopes or on the forest roadside with an altitude range of 324 m to 1621 m (mainly 601 m to 1237 m) and a slope range of 0° to 42° (mainly 6° to 26°). A total of 293 taxa were identified from 64 quadrates of natural populations in the Korean peninsula including Mt. Baekdu. Direct threats were observed to be human activities, competition among plants, and disturbance from fallen leaves.
Based on the conservation biology study, the conservation status of Korean endemic Pseudostellaria species were classified according to the IUCN Red List Categories and Criteria-Version 3.1 second edition. The extend of occurrence (EOO) and area of occupancy (AOO) were calculated by distribution maps based on field surveys and specimen information. Only mature individuals were considered in the population size. P. baekdusanensis was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ), C2a(ⅰ), D1. P. okamotoi was classified as Endangered B1ab(ⅲ) + B2ab(ⅲ). P. okamotoi var. longipedicellata was classified as Endangered B2ab(ⅲ). P. palibiniana var. gageodoensis was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ). P. setulosa was evaluated as Endangered B1ab(ⅲ) + B2ab(ⅲ). P. davidii x P. okamotoi var. longipedicellata was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ), C2a(ⅰ), D1. P. heterophylla x P. okamotoi var. longipedicellata was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ), C2a(ⅰ), D1. P. x seoraksanensis was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ), C2a(ⅰ), and D1. P. x segeolsanensis was classified as Critically Endangered B1ab(ⅲ) + B2ab(ⅲ), C2a(ⅰ), D1.