Phedimus daeamensis T.Y. Choi & D.C. Son, 2022

Choi, Tae-Young, Son, Dong Chan, Shiga, Takashi & Lee, Soo-Rang, 2022, Phedimus daeamensis (Crassulaceae), a new species from Mt. Daeam in Korea, PhytoKeys 212, pp. 57-71 : 57

Phedimus daeamensis T.Y. Choi & D.C. Son sp. nov.

Fig. 1

Type.

Republic of Korea. Gangwon-do , Inje-gun , Buk-myeon , Wolhak-ri, Mt. Daeam. Elevation 1,000 m. 20 August 2014. K.H. Lee & S.K. So 0001 (holotype KH; isotypes 2 sheet, KH) .

Perennial herbs.

Rhizome woody, elongated. Roots not tuberous; rootstock not robust. Stems numerous, more basally branched, tufted, creeping, ascending, 12-21 cm long, glabrous. Leaves alternate, sessile, coarsely arranged; leaf blade obovate, 1-2.3 cm long, 0.5-1.2 cm wide, flat, base narrowly cuneate, margin apically to mid serrate 4-5 ×, entire at base, apex obtuse; lower leaves almost all entire. Inflorescence corymbiform-cymose, many-flowered; bracts leaf-like. Flowers bisexual, mostly 5-merous, shortly pedicelled. Calyx tube 2.1-3.2 mm long; lobes spurless, lanceolate, 1-1.2 mm long, apex obtuse. Petals free, yellow, lanceolate to oblong, 5-6.5 mm long, abaxially keeled, apex acuminate, spreading at anthesis. Stamens 10, in 2 series, erect, shorter than petals, those opposite to petals adnate to them to 1/4 of length from the base; anthers red, ellipsoid, ca. 1 mm long; filaments yellow. Pistils 4.5-5 mm long; ovaries ca. 2.5 mm long, connate at the base; styles slender, 2-3 mm long. Carpels 5, erect, equaling or slightly shorter than the petals, adaxially gibbous, shortly connate at the base. Follicles greenish, stellately and horizontally spreading, ca. 4 mm long, with a very short beak. Seeds 0.8-0.9 mm long, brown, obovoid, scalariform, ribbed, striate.

Flowers in May to June, fruiting in July to August.

Distribution and habitat.

Republic of Korea (Prov. Gangwon). Stony cliffs and rock crevices, at ca. 1000 m.

Etymology.

The specific epithet, " daeamensis ", is based on the name of the location, Mt. Daeam, where Phedimus daeamensis was discovered.

Korean name.

Dae-am-gi-rin-cho.

Molecular diagnosis.

In total, 32 sequences of two DNA regions (ITS and psb A- trn H IGS) were newly obtained from the 16 accessions of P. daeamensis and the six most closely related taxa (Suppl. material 1: Table S3). We also used 15 sequences from eight accessions obtained from GenBank ( P. aizoon var. floribundus , P. latiovalifolius , P. takesimense ) for the phylogenetic analysis. The lengths of the ITS and psb A- trn H IGS alignment were 588 and 272 base pairs, respectively (Table 2 ). After an alignment of 24 accessions, we found 173 variable sites and 144 of these were parsimony informative (Table 2 and Suppl. material 1: Table S6). Overall, the GC ratio was 50.5% and 22.5% for ITS and psb A- trn H IGS, respectively (Table 2 ). K2P genetic distances among in-group individuals ranged from 0 to 0.043 (mean 0.023) for ITS and 0 to 0.048 (mean 0.018) for psb A- trn H IGS (Table 2 ). We also found a 6 bp inversion in the psb A- trn H IGS of all P. daeamensis accessions and one accession of P. takesimensis (Suppl. material 1: Table S6). We excluded this inversion from further phylogenetic analysis.

Overall, the inferred phylogenies from the two regions differ, particularly in the basal nodes (Figs 2 , 3 ). There was a congruence between the ML and BI trees inferred from the ITS and psb A- trn H IGS data sets (Figs 2 , 3 , Suppl. materials 2, 3: Figs S1, S2; posterior probabilities are indicated in ML trees). In the psb A- trn H IGS trees, P. daeamensis was separated but formed an unresolved polytomy (Fig. 3 and Suppl. material 3: Fig. S2). Phedimus sikokianus formed a monophyletic group, whereas all other species showed more complicated and mixed clustering patterns (Fig. 3 and Suppl. material 3: Fig. S2). In the ITS trees, two major clades were recognized, but only clade 1 was statistically robust (Fig. 2 and Suppl. material 2: Fig. S1). The three samples of the putative new species, P. daeamensis , formed a well-supported monophyletic clade (bootstrap value; BS = 95%; posterior priority; PP = 0.99) that was separated from the other species. Phedimus daeamensis again formed a clade together with P. middendorffianus (one sample) and P. takesimensis (three samples), but the statistical support was very weak (Fig. 2 and Suppl. material 2: Fig. S1). All accessions of P. sikokianus formed a well-supported clade (BS = 95.9%; PP = 0.99) with samples of P. kamtschaticus and P. aizoon , both of which were not monophyletic (Fig. 2 , Suppl. material 2: Fig. S1). Phedimus latiovalifolius was nested within a clade containing samples of P. kamtschaticum and P. aizoon (Fig. 2 ).

Figures

Figure 1. Phedimus daeamensis A habit B leaf C flower D petal and stamen E carpel F seed. (Illustrated by Kyungsoo Eo).

Figure 2. Maximum likelihood tree for individuals of Phedimus daeamensis and related taxa based on nrITS. Numbers above branches indicate bootstrap values (> 50 %) and posterior probabilities (> 0.5).

Figure 3. Maximum likelihood tree for individuals of Phedimus daeamensis and related taxa based on psb A- trn H IGS. Numbers above branches indicate bootstrap values (> 50 %) and posterior probabilities (> 0.5).