Carrierea leyensis Z. C. Lu & W. B. Xu, 2024

Lu, Zhao-Cen, Liu, Zhi-Rong, Mo, Ming-Lin, Chang, Shi-Li & Xu, Wei-Bin, 2024, Carrierea leyensis, a new species of Salicaceae from limestone areas of Guangxi, China, PhytoKeys 248, pp. 305-313 : 305-313

Carrierea leyensis Z. C. Lu & W. B. Xu sp. nov.

Figs 1 , 2 , 3

Diagnosis.

Carrierea leyensis Z. C. Lu & W. B. Xu differs from C. dunniana H. Lév. in its evergreen nature; shorter petioles, only 3–8 mm long, and tomentose or glabrous when old; elliptic leaf blades with cuneate base; shorter inflorescences; smaller flowers; and smaller capsules.

Type.

China • Guangxi: Baise City, Leye County, Tongle Township , Fengdong Village , Laomudong , around the point 106.482109 ° E, 24.75169 ° N, in forests of limestone slope, elevation ca. 1330 m, 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18270 (holotype: IBK 00461833 ; isotypes: IBK 00461831 , IBK 00461832 ) .

Description.

Trees or small trees, monoecious, evergreen, 5–12 m tall; bark gray-brown; branchlets grayish, with white lenticels and leaf marks, tomentose, glabrous when old; winter buds conical, scales hairy; stipules absent. Petiole 3–8 mm long, tomentose to glabrous when old; leaf blade greenish abaxially, deep green adaxially, glabrous, elliptic, (2.8 –) 4–9.5 (– 12.5) × 1.7–4.6 cm, leathery or thinly leathery, both surfaces glabrous or abaxially sparsely appressed-villous along midveins, weakly 3 - veined at base, lateral veins 5–8 pairs, veins distinct on both sides, midvein raised below, base cuneate, margin remotely serrate, with spheroidal to torus-shaped glands at the tips of the teeth (salicoid teeth), apex acuminate to long acuminate. Inflorescence terminal or axillary, 2–11 - flowered, rarely single flower axillary, 1.8–4.5 cm long including flowers, tomentose, pistillate flowers in terminal part of inflorescence, staminate ones in lower part; bracts ovate-lanceolate, 1–1.35 cm long, papery, both surfaces sparsely to densely tomentose. Pedicels 0.5–2.5 cm long, 2 - bracteolate near middle; bracteoles similar to bracts, opposite, narrowly oblong, 3–7 mm long, papery, both surfaces sparsely to densely tomentose. Sepals (2 or 3 rare) 4–5, valvate, ovate-deltoid to oblong, 3.5–8 × 2–3 mm, papery, both sides tomentose, apex acute. Petals absent. Staminate flowers: smaller than pistillate flowers, stamens with filaments unequal in length, 2–3 mm long, glabrous; anthers ca. 0.5 mm long. Pistillate flowers: staminodes like stamens but much reduced; ovary superior, elliptic, densely tomentose, 0.6–1 cm long; placentas 3 or 4; styles 3 or 4, 0.5–1 mm long, connate at least at base to form a column, sparsely tomentose like the ovary; stigmas reflexed, drying black, flattened, triangular, 2–3 mm long, irregularly lobed, glabrous. Capsule fusiform, slightly curved, 1.7–2.7 cm long, 5–9 mm in diam., tomentose, valves splitting from both apex and base; fruiting pedicel stout, 1–2.8 cm long; seeds compressed, including wing 9–12 mm long; sterile seeds smaller.

Etymology.

The specific epithet ‘ leyensis ’ refers to the locality where the new species was collected.

Phenology.

Flowering April to May (spring); fruiting July to October (summer to autumn).

Distribution and habitat.

Carrierea leyensis has only been collected from limestone areas of Leye County, Baise City, Guangxi, China. It grows sporadically in forests on limestone slopes, at an elevation of 1100–1350 m. Associated species include Handeliodendron bodinieri (H. Lév.) Rehder , Pistacia chinensis Bunge , Pittosporum tonkinense Gagnep. , Machilus cavaleriei H. Lév. , Triadica rotundifolia (Hemsl.) Esser , Jasminum lanceolaria Roxb. , Eriobotrya seguinii (H. Lév.) Cardot ex Guillaumin , Carex brunnea Thunb. , Ophiorrhiza species, and Carpinus species.

Conservation status.

The new species has been found in three localities in Leye County, Baise City, Guangxi, China. We did not complete additional surveys in the area, so the number of living populations is unknown. According to the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Committee 2022), Carrierea leyensis should be considered in the Data Deficient (DD) category at present.

Additional specimens examined

(paratypes). China • Guangxi: Baise City, Leye County, Tongle Township , Fengdong Village , around the point 106.502383 ° E, 24.769041 ° N, limestone slope, alt. 1190 m, 30 July 2023, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 16830 ( IBK, GXMG, IBSC) ; • ibid., 30 July 2023, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 16832 ( IBK, PE, KUN) ; • ibid., 10 October 2023, W. B. Xu, Z. C. Lu, S. L. Chang & J. Q. Huang 17742 ( IBK, CSH) ; • Tongle Township, Longmen Village, Caojiadongtun , around the point 106.456363 ° E, 24.736441 ° N, limestone slope, alt. 1230 m, 31 December 2023, W. B. Xu, Z. C. Lu, S. L. Chang & J. Q. Huang LZC 2195 ( IBK, GXMI) ; • ibid., 24 September 2023, Z. R. Liu LKY-YC 468 ( IBK) ; • ibid., 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18273 ( IBK, CSH) ; • ibid., 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18274 ( IBK, GXMI) ; • Tongle Township, Fengdong Village, Laomudong , around the point 106.481868 ° E, 24.751426 ° N, limestone slope, alt. 1300 m, 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18271 ( IBK, PE, KUN) ; • ibid., 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18264 ( IBK, GXMG, IBSC) ; • ibid., 4 May 2024, W. B. Xu, Z. C. Lu, M. L. Mo, S. L. Chang & J. Q. Huang 18266 ( IBK) .

Notes.

Carrierea leyensis can be easily distinguished from the other two species of Carrierea in its evergreen nature, shorter petioles, the shape of leaf blades, shorter inflorescences, smaller flowers, and smaller capsules. The morphological differences between C. leyensis and the two related species C. dunniana (Fig. 4 A – D ) and C. calycina (Fig. 4 E – I ) are summarized in Table 1 .

This study also provides field documentation that individuals of Carrierea can be monoecious. Although some reports of Carrierea indicate that it is dioecious, our results affirm the observations of Yang and Zmarzty (2007), who noted that the type specimens of C. dunniana and C. calycina had both pistillate and staminate flowers.

Figures

Figure 1. Carrierea leyensis sp. nov. A habit B trunk C flowering branches D fruiting branches E leaf, view from adaxial side F leaf, view from abaxial side.

Figure 2. Carrierea leyensis sp. nov. A flowering branches with staminate flowers and young capsules B inflorescences C staminate flowers in frontal view D pistillate flower in frontal view E pistillate flower in dorsal view F dissection of staminate flower G dissection of pistillate flower H bracts I bracteoles J long-section and cross-section of ovary K capsules L seeds.

Figure 3. The holotype sheet of Carrierea leyensis (IBK).

Figure 4. Carrierea dunniana A flowering branches B inflorescence C staminate flower in frontal view D dissection of staminate flower; Carrierea calycina E flowering branches F inflorescence G pistillate flower in frontal view H pistillate flower in dorsal view I dissection of pistillate flower.