Grewia kentingensis Y. H. Tseng, Chih Y. Chang & C. Y. Lin, 2025

Grewia kentingensis Y. H. Tseng, Chih Y. Chang & C. Y. Lin sp. nov.

Figs 1 A View Figure 1 , 2 A View Figure 2 , 3 A View Figure 3 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Diagnosis.

Grewia kentingensis is similar to G. piscatorum but can be distinguished by its procumbent (vs. erect to ascending) habit, smaller leaf size, serrate (vs. biserrulate) leaf margin, terminal (vs. often leaf-opposed) inflorescences, gynodioecious (vs. trioecious) breeding system, smaller flowers, fewer stamens, smaller fruits, and smaller pollen grains.

Type.

Taiwan. Pingtung County • Hengchun Township, Sheding Formosan Sika Deer Restoration Area , 154 m alt., 21°57'53.0"N, 120°49'39.2"E, 26 June 2024, C. Y. Lin et al. 93 (holotype: TCF; isotype: TNM) GoogleMaps .

Description.

Procumbent shrubs to ca. 5 cm tall, stems rooting at the nodes; young branchlets puberulent, older branchlets nearly glabrous. Leaf blades broadly elliptic to elliptic, 0.4–1.6 cm long, 0.3–1.3 cm wide, apex rounded to obtuse, base cuneate to rounded, 3 - nerved, margin serrate, nearly glabrous, stellate hairs sparsely distributed along the veins on both surfaces; petioles 0.4–1.3 (– 1.7) mm long, stellate hairs sparse; stipules linear, 0.4–1.2 mm long. Inflorescences terminal, cymose or flowers solitary; peduncles 0.7–2.7 mm long, 1 to 3 (4 to 6) flowers, pedicels 0.9–4.9 mm long; bracts linear, 0.7–1.4 (– 1.8) mm long. Flowers bisexual or functionally unisexual (female), bisexual flowers 7.2–11.7 mm diam., female flowers 5.2–7.8 mm diam. Sepals (3) 4 to 5, narrowly oblong to oblong, bisexual flowers 4.5–6.0 mm long, 1.4–2.3 mm wide; female flowers 3.2–4.8 mm long, 0.9–1.9 mm wide, apex acute, abaxial surface yellowish green, stellate – pubescent, adaxial surface white, glabrous. Petals (3) 4 to 5, oblong to ovate, apex rounded, bisexual flowers 1.1–1.5 mm long, 0.6–0.9 mm wide, female flowers 1.2–1.6 mm long, 0.7–0.9 mm wide; nectaries present at the base of adaxial surface, 0.6–0.9 mm diam., surrounded by ciliate hairs. Androgynophore cylindrical, bisexual flowers 0.7–0.9 mm long; female flowers 0.8–0.9 mm long, glabrous, ciliate hairs only at the apex. Ovary globose to oblate, pubescent, bisexual flowers 0.8–1.0 mm diam.; female flowers 0.8–1.0 mm diam. Bisexual flowers with stamens 25 to 33, filaments white, glabrous, 1.2–3.2 mm long, anthers dehiscing longitudinally; style (1.8 –) 2.3–2.7 mm long, glabrous, stigma 4 - lobed, each lobe dentate at apex. Female flowers with 15–20 stamens, filaments white, glabrous, 0.6–1.1 mm long, anthers white, always indehiscent; style 1.3–2.2 mm long, glabrous, stigma 4 - lobed, each lobe dentate at apex. Fruits drupaceous, usually 4 - lobed, fruit lobe 4.1–5.2 mm diam., globose, puberulent to nearly glabrous, red when mature.

Phenology.

Flowering from May to August and fruiting from June to September.

Distribution and habitat.

The species is endemic to Taiwan. Grewia kentingensis is sparsely distributed only on the elevated coral reefs and the coastal open grasslands at 50–200 m alt. along the eastern coastline of the Hengchun Peninsula. Commonly associated species include Maytenus diversifolia (Maxim.) Ding Hou ( Celastraceae ), Pandanus odorifer (Forssk.) Kuntze. ( Pandanaceae ), Phoenix loureiroi Kunth var. loueiroi (Palmae) , Rostellularia hayatae (Yamam.) S. S. Ying ( Acanthaceae ), Galactia tashiroi Maxim. ( Fabaceae ), and Cirsium albescens Kitam. (Compositae).

Chinese name.

kěn-dīng-bǔ-yú-mù (墾丁捕魚木)

Etymology.

The species epithet kentingensis refers to the type locality of Kenting in Hengchun Peninsula, Pingtung County, Taiwan.

Palynology.

Pollens grains are tricolporate, subprolate to prolate, 35.8–41.4 × 24.1–33.4 μm. Exine reticulate, with muri 0.6–0.8 μm wide and lumen 1.0–2.9 μm. Perforations present in the lumen, 0.04–0.24 μm.

Conservation status.

Grewia kentingensis has an extremely limited distribution on the Hengchun Peninsula and is known from 12 collections representing three populations. It has a geographic range in the form of an estimated EOO of 8 km 2 (adjusted upward from 1.423 km 2 following IUCN 2024) and an AOO of 8 km 2. Even though the distribution of the species is located within the areas of Kenting National Park, its habitat is threatened by grazing, wildfires, and invasive plant species ( Cuscuta campestris Yunck. , Stachytarpheta jamaicensis (L.) Vahl , and Bidens pilosa var. radiata (Sch. Bip.) J. A. Schmidt ). Given these ongoing threats, we infer a continuing decline in the area, extent and quality of habitat. With respect to the most serious plausible threat of wildfire, the three occurrences represent one location, which falls within the limits for “ Critically Endangered ” status. Grewia kentingensis is therefore preliminarily assessed as “ Critically Endangered ” [CR B 1 ab (iii) + 2 ab (iii)] in accordance with the IUCN Red List Categories and Criteria ( IUCN 2024). The above analysis is based on the specimens cited and georeferenced as shown in Table 4 View Table 4 .

Specimens examined.

Taiwan. Pingtung County • Fongchueisha , 28 Jun 1988, T. C. Huang & S. F. Huang 13542 ( TAI) • Ibid., 23 Jul 2013, K. C. Chang 4893, 4894 ( CHIA) • Ibid., 29 Mar 2015, C. Y. Chang & C. H. Liu 397 ( TNM) • Ibid., 3 May 2024, C. Y. Lin et al. 69 ( TCF) • Longzaipu , 6 Sep 2008, P. F. Lu 16921 ( TAIF) • Ibid., 17 Sep 2008, T. C. Hsu 1743 ( TAIF) • Ibid., 23 Jul 2013, C. M. Wang et al. 15470 ( TNM) • Ibid., 14 Aug 2013, C. F. Chen 4697 ( TAIF) • Ibid., 12 Apr 2014, C. Y. Chang 30 ( PPI) • Sheding , 12 Aug 1995, Y. H. Yu 7968 ( TAIF) • Sheding Formosan Sika Deer Restoration Area , 15 Jan 2021, C. Y. Chang et al. 3236 ( TNM) .