Chrysosplenium guangxiense H. G. Ye & Gui C. Zhang

Fu, Long-Fei, Yang, Tian-Ge, Lan, De-Qing, Chen, Xi-Tang & Liu, Hong, 2024, Molecular and morphological evidence supports the resurrection of Chrysosplenium guangxiense H. G. Ye & Gui C. Zhang (Saxifragaceae), PhytoKeys 243, pp. 185-198 : 185-198

Chrysosplenium guangxiense H. G. Ye & Gui C. Zhang in Acta Bot. Austro Sin. 9: 57, f. 1 (1994)

Figs 3 , 4

Type.

Tian Lin , 11 Oct. 1989, South China Exped. 2458 (holotype: IBSC!; isotype: IBSC!) .

Description.

Perennial herbs, 5.5–17 cm high. Root fibrous and robust. Long creeping rhizome developed, thick, crossed and nodular, 1–2 cm between each node, without stolons and bulbs. Flowering stem (s) always 1, erect, branched, 10–17 cm high, sparsely pilose, green, squared. Sterile branches arise from all basal leaves. Isophyllous, Basal leaves 3–6, alternate and clustered; petiole 1–6.5 cm long, white pilose; leaf blade long elliptic, 2.2–10.3 × 1.8–3.3 cm, abaxially glabrous, light green, adaxially with sparse long hispid, dark green, apex rounded, margin 14–25 - crenate, base long cuneate. Cauline leaves always 1, petiole 1.3–2.2 cm long; blade 2.2–4.0 × 1.2–1.9 cm, long elliptic, glabrous in the abaxial side and with sparse hispid in the adaxial side; apex obtuse; margin obtusely dentate (9–13 teeth); base broadly cuneate; veins obvious in adaxial. Pleiochasium 9–16 cm wide, 10–15 cm high, extremely diffused, with 5–20 - flowered cyme, branches sparsely hispid, surrounded by bracts; bracteal leaves green, elliptic to broadly ovate or round, glabrous. Flowers tetramerous, actinomorphic; sepals 4 (2 pairs), flat, green, 0.9–1.2 × 2.1–4.3 mm, broadly ovate, apex acute, with margin curls outward in fruiting time; disk obvious; stamens 8, ca. 0.2 mm long, shorter than sepals; anthers orange, 2 - locular, longitudinally dehiscent; ovary 2 - locular, semi-inferior; stigma 2; styles erect, ca. 0.2 mm long. Fruit a capsule, 5–7 mm long, green, smooth, 2 - lobed (horn-shaped), equal, dehiscent along the adaxial suture; seeds numerous, red or reddish brown, obovoid, a raphe on one side, 594.19–855.33 × 475.41–625.7 μm, long papillose. Viviparous.

Additional specimen examined.

Chrysosplenium glossophyllum . China. Sichuan: Kuan County ( Dujiangyan City ), 19 April 1930, F. T. Wang 20553 ( PE!, NAS!) ; same locality, 6 May 1987, Xintang Ma & Zhilong Zhao 87-0521 ( WCSBG!) ; same locality, 15 April 2013, LiXJ 353 ( KUN!) ; same locality, 24 May 2016, Hong Liu, HSN 06644 ( HSN!) ; same locality, 26 October 2017, Hong Liu, HSN 08105 ( HSN!) . Chrysosplenium guangxiense . China. Guangxi: Lingyun County, Baise City , 6 March 2014, Lingyun team 451027140305005 ( GXMG!) ; Tianlin County, Baise City , 27 November 2019, Hong Liu HSN 13356 ( HSN!) .

Conservation status.

Chrysosplenium guangxiense is only known from two localities ( IUCN criterion D 2). At these two localities, the populations included ca. 200 mature individuals ( IUCN criterion D 1) growing in several patches. Using the IUCN methodology, C. guangxiense is classified as Vulnerable ( VU) based on criteria D 1 and D 2: population size and the number of locations, combined with a plausible future threat that could drive this taxon to Critically Endangered or Extinct in a very short time. However, the vivipary of C. guangxiense may strengthen its adaptability to cope with future climate and environmental changes. The future threat is mainly due to grazing.

Figures

Figure 3. Illustration of Chrysosplenium guangxiense H. G. Ye & Gui C. Zhang A habit in flowering phase B flower C indehiscent capsule D dehiscent capsule and seeds E germinated seeds in capsule F seeds G caulline leaf H, I bracteal leaf. 3

Figure 4. Plate of Chrysosplenium guangxiense H. G. Ye & Gui C. Zhang A habit B, C inflorescence with flowers D, E basal leaves F fruit and seed G, H germinated seeds and seedlings in capsule I, J SEM of seed (Photos by Hong Liu).