Chrysosplenium macrospermum Y.I.Kim & Y.D.Kim, 2019

Kim, Yong-In, Shin, Jae-Seo, Lee, Sangwoo, Chen, Jia-Hui, Choi, Sangho, Park, Jin Hee & Kim, Young-Dong, 2019, A new species of Chrysosplenium (Saxifragaceae) from Northeastern China, PhytoKeys 135, pp. 39-47 : 39

Chrysosplenium macrospermum Y.I.Kim & Y.D.Kim sp. nov. Figs 1 , 2 , 3A1, A2

Diagnosis.

Chrysosplenium macrospermum is most similar to Chrysosplenium valdepilosum (Ohwi) S.H. Kang & J.W. Han, 2011 (see Han et al. 2011), but the former is readily distinguishable by short arching sterile branches, multiple (up to 3) flowering stems, and smooth surfaced seeds (without tubercles), which are ca. 30-50% larger than those of other members in the series Pilosa ( Figure 3 ).

Type.

China. Jilin: near Tianchi (Cheon-Ji in Korean) Crater Lake to Changbaishan Mt. (Beakdusan Mt. in Korean), Antu County, Changchun, 42°01'44.80"N, 128°03'59.22"E, elev. 2,610 m, 26 Jul. 2017, KYI-2017001 (holotype HHU; isotypes HHU, KB, KRIB).

Description.

Perennial herbs. Small (up to 7 cm), hermaphroditic. Roots thick fibrous. Flowering stem(s) 1-3, erect, 2-7 cm long, sometimes branched, tetragonal in the cross-section, sparsely pilose along the edges, light green to green, with 2(3) sterile branches arising from the base; sterile branches 1-1.5 cm long, stout, arch-shaped, sparsely pilose. Leaves simple, estipulate, petiolate. Basal leaves (1) or 2, opposite, petiole 3-15 mm long, blade up to ca. 1 × 1 cm, flabelliform. Cauline leaves of flowering stem(s) 1-4, opposite or rarely alternate, attached at 1/2 or below of the stem; petiole 1-10 mm long, entirely ciliate; blade 2-10 × 3-11 mm, flabelliform, apex subtruncate to rounded, base attenuate, margins obscurely undulate to crenate or distinctly obtusely dentate (3-7 teeth), translucent white or brown ciliate, both surfaces glabrous. Leaves of sterile branches, opposite, 4-8 pairs; petiole 4-15 mm long, entirely ciliate; blade to 1.5 × 1.5 cm, suborbicular or widely ovate to ovate, apex rounded, base cuneate to narrowly cuneate, margins crenate with 3-10 flat obscure teeth, translucent white or brown ciliate, upper surface sparsely pilose near the margin, green to pale green, lower surface sparsely pilose along the veins, greenish grey. Inflorescence 5- to 30-flowered cyme, surrounded by leaf-like bracts; pedicel 1-3 mm long, sparsely pilose. Bracteal leaves yellow during flowering, turning to greenish yellow after anthesis; petiole 1-3 mm long, entirely ciliate; blade 2-9 × 2-10 mm, flabellate, obdeltoid, spatulate, apex obtuse to subtruncate, base narrowly cuneate to cuneate, margins obscurely undulate to crenate or distinctly obtusely dentate, 2-7 teeth, sparsely translucent white or brown ciliate, both surfaces glabrous, greenish-grey. Flowers tetramerous, actinomorphic; sepals 4 (2 pairs), free, petaloid, 1 pair overlapping the other in bud, erect, yellow, 2-4 × 2-3 mm, widely obovate to widely subelliptic, glabrous, 3-veined, apex obtuse to truncate, slightly recurved to outside, persistent; petals absent; stamens 8, biseriate, ca. 2 mm long, shorter than sepal; filaments narrow conical, ca. 1.5 mm long; anthers yellow, 2-locular, ca. 0.5 mm long, longitudinally dehiscent; pistil 2-carpellate, semi-inferior, ovary 1-locular, ovules at 2 parietal placentae, styles 2, free, ca. 1 mm long, stigma round. Fruit a capsule, light green, glabrous, ca. 6 mm long, 2-lobed (horn shaped), lobes slightly unequal, dehiscent along the adaxial suture; seeds numerous, light brown, ellipsoid, with a raphe on one side, thick-walled, 935-1021 × 511-566 μm, seed surface covered with minute deciduous papillae, without tubercles.

Etymology.

The specific epithet of the new species refers to the distinctly larger size of the seeds compared with those of other members in the series Pilosa .

Vernacular name.

Cheon Ji Gwaeng I Nun (Korean pronunciation); 천지괭이눈 (Korean name), Tiān Chí Jīn Yāo (Chinese pronunciation); 天池金腰 (Chinese name)

Distribution.

Chrysosplenium macrospermum is only known from Changbaishan Mt. in Jilin Province of China, at an elevation of ca. 2,600 m. To date, only a few subpopulations with approximately 5,000 individuals have been discovered near Tianchi Crater Lake. In the absence of additional data, we presently score it as Data Deficient (DD) according to the IUCN Red List criteria ( IUCN 2001).

Ecology.

Chrysosplenium macrospermum occurs in alpine tundra, where it grows in humid and semi-shaded areas near the Tianchi volcanic crater along with Papaver radicatum var. pseudoradicatum (Kitag.) Kitag., Bistorta ochotensis Kom., Micranthes laciniata (Nakai & Takeda) S. Akiyama & H. Ohba, Sedum rosea (L.) Scop., and Pedicularis verticillata L. The flowering period of this species is from late May to early July, and the fruiting period is from July to August.

Additional specimens examined (paratype).

China. Jilin: near Tianchi (Cheon-Ji in Korean) Crater Lake to Changbaishan Mt., Antu County, Changchun, 25 Apr. 2014, D.K. Lee-2014001 (HHU), D.K. Lee-2014002 (HHU), D.K. Lee-2014003 (HHU), 42°01'44.80"N, 128°03'59.22"E, elev. 2610 m, 26 Jul. 2017, KYI-2017002 (HHU), KYI-2017003 (HHU), KYI-2017004 (HHU), KYI-2017005 (HHU), KYI-2017006 (KB).

Notes.

The new taxon and C. valdepilosum exhibit a high degree of morphological similarity upon flowering ( Fig. 3 ) but can be distinguished by several characters, including the size of the seed, the excrescence of the seeds, the developmental form of the sterile branch, and the hair type on the leaves of the sterile branch (Table 1 ). Chrysosplenium macrospermum occurs only in the vicinity of Tianchi Lake (elev. 2190 to 2610 m). It is the only species of the series Pilosa that grows in the vast Changbaishan Mt. region. The geographical distributions of other members of series Pilosa , including C. valdepilosum (endemic to Korea), do not overlap with that of C. macrospermum .

Figures

Figure 1. Chrysosplenium macrospermum Y. I. Kim & Y. D. Kim, sp. nov. A flowering individual B fruiting individual C inflorescence and bracteal leaves D infructescence and bracteal leaves E seed F seed coat, enlarged G flower (top view) H capsule, after dehiscence (top view) I stamen at various stages J capsule with persistent sepals (side view) K capsule, sepals removed L capsule, longitudinal section.

Figure 2. Chrysosplenium macrospermum Y. I. Kim & Y. D. Kim, sp. nov. A fruiting individual B infructescence, bracteal leaves and seeds in capsules C plant habit during flowering D fruiting individual showing short arch-shaped sterile branches and thick fibrous roots.

Figure 3. Chrysosplenium spp. inflorescence and seeds. A C macrospermum Y. I. Kim & Y. D. Kim, sp. nov., inflorescence with bracteal leaves (A 1), seed surface, scanning electron micrograph, 140 x (A 2) and 600 x (A 3) B C. valdepilosum, inflorescence with bracteal leaves (B 1), seed, scanning electron micrograph, 350 x (B 2) and 600 x (B 3). White solid arrows indicate deciduous papilla (A 3, B 3) and blanked arrows indicate tubercle (B 2, B 3).