Artabotrys pachypetalus B.Xue & Junhao Chen, 2021

Xue, Bine, Wang, Gang-Tao, Zhou, Xin-Xin, Huang, Yi, Tong, Yi, Li, Yongquan & Chen, Junhao, 2021, Artabotrys pachypetalus (Annonaceae), a new species from China, PhytoKeys 178, pp. 71-80 : 71

Artabotrys pachypetalus B.Xue & Junhao Chen sp. nov. Figs 1 , 2

Chinese name.

Hou ban ying zhua hua (厚瓣鹰爪花)

Diagnosis.

Similar to Artabotrys punctulatus C.Y.Wu ex S.H.Yuan in having multi-flowered inflorescences and similar outer and inner petal length (9-20 mm long), but differs in having non-punctate (vs. densely punctate) abaxial leaf lamina, cream (vs. beige, maroon-tinged) petals in vivo, connivent (vs. spreading) inner petal blades in vivo, a short, ca. 1 mm long (vs. an elongate, ca. 5 mm long) raised rim above the inner petal claw, and thick pericarp (2-3 mm thick vs. less than 1 mm thick).

Type.

China. Guangdong Province, Yangchun, Chun-wan Town, Zi-you Village , Ma-tang , alt. 110 m, limestone, 08 Apr. 2019, X.X. Zhou, G.T. Wang & Y.N. Guo 0028 (holotype: IBSC [barcode no. IBSC0861926]; isotypes: KUN, SING) .

Description.

Climbers ca. 7 m tall. Twigs drying brown, glabrous to sparsely appressed-pubescent when young. Leaf laminas chartaceous, 10-16 cm long, 3.5-5.0 cm wide, length:width ratio 3-4(-5), narrowly oblong, apex acute or acuminate to cuspidate, base cuneate, glabrous both ab- and adaxially; midrib appressed-pubescent abaxially, glabrous adaxially, raised on both surfaces; secondary veins 8-13 pairs per leaf, impressed adaxially, raised abaxially; tertiary venation reticulate, visible on both surfaces; petioles 3-5 mm long, ca. 1 mm in diameter, glabrous to sparsely appressed-pubescent, drying with transverse striations. Inflorescence axis recurved, laterally compressed, hook-like, with 6-10 flowers; flowering pedicels 6-15 mm long, ca. 1 mm in diameter, densely spreading-pubescent. Sepals 3, free, coriaceous, valvate at base, ca. 5 mm long, ca. 5 mm wide, triangular, glabrous adaxially, sparsely appressed-pubescent abaxially. Petals 6, in two whorls of 3 inner and 3 outer petals, free, valvate, coriaceous when dry, cream in vivo, with distinct upper blade and concave base. Outer petals 3, 9-14 mm long; blades spreading, ca. 5-9 mm long, 3-7 mm wide, ca. 1 mm thick, ovate, densely appressed-pubescent both ab- and adaxially, apex rounded; claws 4-5 mm long, 4-8 mm wide, densely appressed-pubescent abaxially, glabrous adaxially. Inner petals 3, 11-17 mm long; with a short, ca. 1 mm long raised rim above the claw; blades connivent, 7-11 mm long, 4-6 mm wide, ca. 2 mm thick, somewhat trigonal or terete in vivo, densely appressed-pubescent both ab- and adaxially, apex rounded; claws ca. 4-6 mm long, 3-5 mm wide, densely appressed-pubescent abaxially, glabrous adaxially, tinged orange-red at the very base in vivo. Stamens extrorse, ca. 50-60 per flower, ca. 2 mm long, ca. 1 mm wide; apex of connectives rounded, with a sharp edge adaxially, orange red in vivo. Carpels 8-20 per flower, ca. 3.5 mm long, glabrous; ovaries ellipsoid, ca. 1.5 mm long, ca. 0.6 mm wide, glabrous; ovules 2, basal; stigmas 1.5-2 mm long, cylindrical to slightly clavate, glabrous. Fruiting pedicels 10-20 mm long, ca. 3 mm in diameter, subglabrous. Monocarps 8-20 per fruit, unripe monocarps in vivo light green, at maturity unknown, drying black, 25-30 mm long, 15-22 mm wide, ellipsoid, glabrous, subsessile or with stipes up to ca. 2 mm long, apex rounded, pericarp 2-3 mm thick. Seeds 2 per monocarp, light yellow, smooth, plano-convex, 16-20 mm long, 12-14 mm wide, 10-12 mm thick, raphe depressed, endosperm ruminations lamelliform.

Etymology.

The specific epithet ' Artabotrys pachypetalus ' alludes to the thick inner petals.

Phenology.

Flowering in April; fruiting in August to December.

Distribution and habitat.

Guangdong, Guangxi, Guizhou, Hunan and Jiangxi (Fig. 3 ), at 100-1400 m elev, mainly growing on limestone.

Additional specimens examined

(Paratypes). China. Guangdong: Yangchun City, Chun-wan Town, Zi-you Village, Ma-tang, alt. 110 m, limestone, 13 Apr. 2020, Y. Huang 341 (IBSC, SING); ibid., 19 Apr. 2020, B. Xue XB342, XB343 (IBSC, SING); Ru-yuan Hsien, 21 Oct. 1939, S.K. Lau 29060 (IBSC, PE); Ru-yuan Hsien, Da-qiao Town, Da-fu village, forest valley, alt. 550 m, 13 Apr. 2013, L. Wu & Y. Tong 3234 (BNU). Guangxi: Feng-shan Hsien, Qiao-yin Town, Ba-la-hou Mountain, limestone, forest edge, alt. 940 m, 3 Mar. 2013, B.Y. Huang, X.Y. Hu & J.J. Yao 451223130331025LY (GXMG); Qi-cheng Hisen, Cui-ping Mountain, alt. 270 m, limestone, 5 May 1983, C.Z. Gao & A.Y. Lan 61263 (GXMI); Na-po Hisen, Nong-bu, alt. 1200 m, limestone, 02 May 1981, Ding Fang et al. 25102 (GXMI). Guizhou: Li-bo Hsien, Mao-lan, 21 Apr. 1981, J.Q. Zhang 1144 (CCNU, GF, GZAC); ibid., alt. 730 m, 8 May 1981, R.B. Jiang 81-0080 (GF, IBSC); ibid., 8 May 1981, R.B. Jiang 80 (CCNU); ibid., 8 May 1981, M.Z. Yang 810247 (HGAS); ibid., alt. 750 m, 7 Mar. 1982, Y.K. Li 10039 (IBSC); ibid., alt. 710 m, 6 Sep. 1982, Y.K. Li 10462 (HGAS); ibid., alt. 800-1000 m, limestone, 03 Apr. 1984, Z.R. Xu L1224 (IBSC); ibid., 26 Apr. 1984, K.M. Lan 840097 (GFS, GZAC); ibid., 02 May 1984, K.M. Lan 841268 (GFS, GZAC); ibid., 2 May 2005, Q.W. Sun 0505019 (GZTM); Xing-ren Hsien, alt. 1300 m, 28 Jun. 1986, C.Z. Dang & P. Dang 156 (PE); Ce-heng Hsien, 21 May 1977, anonymous 071, 77-1635 (HGAS); ibid., alt. 1400 m, 5 Sep. 1958, Z.Y. Cao 0575 (PE); Wang-mo Hsien, Chengguan, forest valley, 15 May 1977, anonymous 77-1594 (HGAS); ibid., 15 May 1977, C.Z. Dang 030 (HGAS). Hunan: Yi-zhang Hsien, Mang Mountain, forest valley, alt. 430 m, 16 Oct. 1942, S.H. Chun 2490 (IBSC, IBK). Jiangxi: Ganzhou City, Long-nan Hsien, Jiu-lian Mountain, limestone, alt. 596 m, 05 Apr. 2021, J.Y. Xu, L.X. Yuan, Y.R. Wang, J.R. Chen JLS-304 (SYS); ibid., 09 Jun. 1970, Group-236 0852 (PE).

Figures

Figure 1. Photographs of Artabotrys pachypetalus sp. nov. A habit B adaxial leaf surface, showing the raised midrib C hooked inflorescence with many loosely clustered flowers D apical view of the flower E basal view of the flower F lateral view of the flower G longitudinal section of the flower, showing the clavate stigma and orange-red stamen connective apex H dissected flower, showing three sepals, three outer petals and three inner petals, and many carpels and stamens (Y. Huang 341, IBSC) I developing young fruit with many monocarps (B. Xue XB 342, IBSC) J dried fruit on old branch (B. Xue XB 342, IBSC) K seed (B. Xue XB 342, IBSC) L longitudinal section of the seed, showing lamelliform endosperm ruminations (B. Xue XB 342, IBSC). Photos: Yi Huang (A, H); Gang-Tao Wang (B-E, G); Yi Tong (F); Bine Xue (I-L).

Figure 2. Illustration of Artabotrys pachypetalus sp. nov. A flowering branch, showing the hooked inflorescence with multiple flowers B lateral view of the flower C adaxial view of the flower, showing three outer petals and three inner petals forming a closed floral chamber D adaxial view of the sepals and torus with stamens and carpels E abaxial view of the sepals F adaxial view of the outer petal G abaxial view of the outer petal H adaxial view of the inner petal I abaxial view of the inner petal J adaxial view of the stamen, showing the rounded connective apex with a sharp edge K abaxial view of the stamen, showing four thecae L carpel, showing the clavate stigma and two basal ovules M immature fruit N seed. Drawn by Yun-Xiao Liu, X. X. Zhou, G. T. Wang & Y. N. Guo 0028 (A-L); B. Xue XB 342 (M, N).

Figure 3. Distribution of Artabotrys pachypetalus sp. nov.