Chrysosplenium sangzhiense Hong Liu,

Fu, Long-Fei, Yang *, Tian-Ge, Lan, De-Qing, Wen, Fang & Liu, Hong, 2021, Chrysosplenium sangzhiense (Saxifragaceae), a new species from Hunan, China, PhytoKeys 176, pp. 21-32: 21

publication ID

http://dx.doi.org/10.3897/phytokeys.176.62802

persistent identifier

http://treatment.plazi.org/id/7D5FF645-2A2F-55D7-96FB-7EF1109D1244

treatment provided by

PhytoKeys by Pensoft

scientific name

Chrysosplenium sangzhiense Hong Liu
status

sp. nov.

Chrysosplenium sangzhiense Hong Liu  sp. nov. Figs 3View Figure 3, 4View Figure 4, 5View Figure 5

Remarks.

Similar to Chrysosplenium grayanum  , C. nepalense  , C. sinicum  and C. cavaleriei  (Table 2). C. sangzhiense  differs from C. grayanum  in its usually fewer cauline leaves, a square flowering stem and red-brown seeds; from C. nepalense  it differs in its usually fewer cauline leaves, a square flowering stem and conspicuously unequal capsule lobes; from C. sinicum  it differs in producing sterile shoots from all leaf axils, an absence of basal leaves, larger cauline leaves, and red-brown seeds; and from C. cavaleriei  it differs in its erect sepals and absent disc.

Type.

China. Hunan: Badagongshan National Nature Reserve , Sangzhi County, 29°47'10"N, 110°5'33"E, under broadleaved forests and near the stream in a mountain area at ca 1,220 m altitude, 22 April 2017, Hong Liu HSN07449View Materials (holotype HSN; isotypes HSN, IBK)GoogleMaps  .

Description.

Perennial herbs, 10-25 cm tall. Root fibrous and robust. Rhizome long creeping without stolons or bulbs. Basal leaves absent. Sterile shoots well developed, arising from all leaf axils, round in cross-section, 5-15 cm long at anthesis, later elongate and decumbent, up to 50 cm long, rooting at nodes, without forming a rosette. Leaves of sterile shoots opposite, isophyllous, always ca 8 at anthesis, dark purple, petiole 6-10 mm long, blade 10-30 × 10-25 mm, rounded, glabrous, apex obtuse, margin obtusely dentate (10-16 teeth), base broadly cuneate; post-anthesis 10-30 or more, green, petiole 6-10 mm long, blade 20-35 × 15-20 mm, rounded or ovate, glabrous, apex obtuse, margin obtusely dentate (12-20 teeth), base broadly cuneate. Cauline leaves 4-6 (2-3 pairs), opposite, petiole 6-10 mm long; blade 6-13 × 5-12 mm, rounded or broadly ovate, glabrous, apex obtuse, margin obtusely dentate (10-14 teeth), base broadly cuneate. Flowering stem(s) erect, branched, 10-23 cm tall, glabrous, purple, square in cross-section. Inflorescence 8-25-flowered cyme, dense, 1.4-9 cm long, 5-10 cm in diam.; bracteal leaves yellow-green, triangular arrangement and unequal, the middle one larger, petiole 2-8 mm long, blade 4-15 × 7-10 mm, subrounded, glabrous, apex obtuse, margin obtusely dentate (6-12 teeth), base broadly cuneate; Flowers tetramerous, actinomorphic; sepals 4 (2 pairs), erect, yellow in flowering phase but turn green in fruiting time, 2-3 × 2-3 mm, broadly ovate, apex obtuse; disk absent; stamens 8, homostylic, 1-2 mm long, shorter than sepals; filaments slender, ca 1 mm long; anther yellow, 2-locular, longitudinally dehiscent; ovary 2-locular, semi-inferior; stigma 2; styles erect, ca 1-2 mm long. Fruit a capsule, 5-7 mm long, green, smooth, 2-lobed (horn-shaped), conspicuous unequal, dehiscent along the adaxial suture; seeds numerous, reddish brown, sub-ovoid, a raphe on one side, 650-800 × 600-750 μm, papillose.

Etymology.

Chrysosplenium sangzhiense  is named after the type locality, Sangzhi County, Hunan Province, China.

Vernacular name.

sāng zhí jīn yāo (Chinese pronunciation); 桑植金腰 (Chinese name).

Conservation status.

At present, Chrysosplenium sangzhiense  is only known from a single locality (IUCN criterion D2). At this locality, the population is ca 500 mature individuals (IUCN criterion D1) growing in at least ten patches within a nature reserve. Using the IUCN methodology, C. sangzhiense  would be classed as Vulnerable (VU), however no plausible threat could be found to confirm its status as the population is located within a protected area and not under threat in the near future. In addition, considering that the surrounding area has not been completely explored, there may be hitherto undocumented additional populations. For these reasons the Global Species Conservation Assessment for C. sangzhiense  is Least Concern (LC).