Based on molecular phylogenetic analyses and field observations, we propose the following taxonomical changes, including one new species, one new name, two new combination, and three new synonyms.
Taxonomic treatments
Primulina chingipengii W.B.Xu & K.F.Chung, sp. nov.: TYPE: CHINA, Guangxi, Du’an County, Chengjiang Town, Baxian Park, 23°54′59.11″N, 108°08′03.26″E, alt 235 m, 8 Oct 2016, W.-B. Xu et al. 13158 (holotpye IBK, isotype HAST). 彭鏡毅小花苣苔 (Figs. 11 and 12).
Diagnosis: Primulina chingipengii is similar to P. cordifolia (Fig. 2h–k) in corolla shape, differing by the leaf blade carnose, broadly ovate, cordate to suborbicular, 2–3 × 1.2–2 cm, densely pubescent on both surfaces, base broadly cuneate, round to cordate in the former species.
Description: Herbs perennial. Rhizome subterete, 12–25 mm long, 4.5–9 mm wide. Leaves 8–23, basal, petiolate, carnose, papery when dry; petiole subterete, 2–6 cm long, 2–3 mm wide, densely pubescent; blades broadly ovate, cordate to suborbicular, 2–3 × 1.2–2 cm, densely pubescent on both surfaces, base broadly cuneate, round to cordate, margin repand, apex obtuse to rounded; lateral veins very inconspicuous, 2–3 on each side. Cymes 4–8, axillary, 1–3-branched, 4–15-flowered; peduncle 5-18 cm long, 1–2 mm in diam, spreadly pubescent and glandular-pubescent; bracts 2, opposite, linear-lanceolate, 3–4 × 0.5–0.8 mm, margin entire, pubescent and glandular-pubescent; pedicel 12–21 mm long, pubescent and glandular-puberscent. Calyx 5-parted to base, lobes lanceolate-linear, 3–4 × 0.5–1 mm, apex acuminate, outside pubescent and glandular-pubescent, inside sparsely puberulent, margins entire. Corolla white, 13–15 mm long, outside pubescent and glandular-pubescent, inside sparsely puberulent, with 2 pale purple stripes; corolla tube 10–12 mm long, 5–6 mm in diam. at the mouth, 3–4 mm in diam. at the base; limb distinctly 2-lipped; adaxial lip 2-parted to over the middle, lobes oblong, 2.5–4.5 × 2–3.5 mm; abaxial 3-lobed to over the middle, lobes oblong, 2.5–3.5 × 2.5–3 mm; stamens 2, adnate to 2.7 mm above the corolla tude base; filaments linear, 3.5–5 mm long, geniculate near the middle, sparsely puberulent; anthers 2–2.5 mm long, dorsifixed, glabrous; staminodes 2, 2–3 mm long, apex slightly capitate, glabrous, adnate to ca. 2.5 mm above the corolla tube base. Disc annular, 0.6–0.8 mm in height, margin slightly repand, glabrous. Pistil 10–13 mm long, ovary narrowly ovoid, 3.5–5 mm long, ca. 1.2 mm across, glandular-puberulent and puberulent; style 6–8 mm long, glandular-puberulent and puberulent; stigma obtrapeziform, ca. 0.5 mm long, 0.5–0.7 mm wide, apex 2-lobed. Capsule narrowly ellipsoidal, 6–8 mm long, 1.6–2.3 mm across, pubescent.
Distribution, habitat and ecology: Primulina chingipengii is only known from its type locality in Baxian Park, Chengjiang Town, Du’an County, Guangxi, China (Fig. 5). It grows on moist rock face at the entrance of a karst cave (Fig. 12a).
Phenology: Flowering from Sep to Oct, fruiting from Nov to Dec.
Etymology: The specific epithet honors Dr. Ching-I Peng (1950–2018), the late Research Fellow of Biodiversity Research Center, Academia Sinica, for his tremendous contribution to our knowledge of the East Asian flora and systematics of Asteraceae, Ludwigia, Begonia, and Sino-Vietnamese karst flora (Chung 2018).
Notes: Primulina chingipengii is similar to P. cordifolia in corolla shape, but it is easily distinguished from the latter by the leaf blades. Phenologically, P. chingipengii and P. cordifolia are also different. Our phylogenetic analyses revealed that P. chingipengii is placed in a strongly supported clade also including P. albicalyx B.Pan & LiH.Yang, P. carinata Y.G.Wei, F.Wen & H.Z.Lü, P. fengshanensis F.Wen & YueWang, and P. pseudoeburnea (D.Fang & W.T.Wang) Mich.Möller & A.Weber (Fig. 4b); however, only P. chingipengii possesses Chiritopsis-like corolla in this clade.
Additional specimens examined (paratypes): Guangxi, Du’an County, Chengjiang Town, Baxian Park, alt 235 m, 8 Oct 2016 W.-B. Xu et al. 13157 (IBK), ibid., 13 Jul 2015, K.-F. Chung et al. 2979 (HAST).
Primulina pseudoglandulosa W.B.Xu & K.F.Chung, nom. nov.: Chiritopsis glandulosa var. yangshuoensis F.Wen, YueWang & Q.X.Zhang in Guihaia 28(3): 291. 2008.—Primulina glandulosa var. yangshuoensis (F.Wen, YueWang & Q.X.Zhang) Mich.Möller & A.Weber in Taxon 60(3): 782. 2011 [non Primulina yangshuoensis Y.G.Wei & F.Wen in Taiwania 57(1): 56, Fig. 1 & 2A. 2012.].—TYPE: CHINA, Guangxi, Yangshuo County, Yulonghe, alt 110–140 m, 24 Jun 2006, F. Wen 06062401 (holotype BJFC, isotype IBK!). 陽朔小花苣苔 (Fig. 13c–g).
Description: Herbs perennial. Rhizome subterete, 3–7 cm long, 8–12 mm wide. Leaves 8–18, basal, petiolate, herbaceous, sometimes slightly carnose; petiole subterete, 4–8 cm long, 1.5–2.5 mm wide, sparsely pubescent; blades broadly ovate, cordate to suborbicular, 5.0–6.5 × 4.5–5.5 cm, sparsely pubescent on both surfaces, base cordate, margin dentate, apex acute to obtuse; subpinnipalmate, 2–3 on each side, sometimes white along the veins. Cymes 3–8, axillary, 1–3-branched, 8–15-flowered; peduncle 7–18 cm long, ca. 1.5 mm in diam, sparsely pubescent; bracts 2, opposite, lanceolate, 7–9 × 2–3 mm, margin entire, pubescent; pedicel 3–10 mm long, pubescent. Calyx 5-parted to base, lobes lanceolate-linear, 6–7 × 0.8–1 mm, apex acuminate, outside pubescent, inside sparsely puberulent, margins entire. Corolla white with pale purple, 10–13 mm long, outside sparsely pubescent, inside sparsely puberulent, with 2 pale purple stripes; corolla tube 6–10 mm long, 4–5 mm in diam. at the mouth, 3–4 mm in diam. at the base; limb distinctly 2-lipped; adaxial lip 2-parted to over the middle, lobes oblong, 1.5–2 × 2–3 mm; abaxial 3-lobed to over the middle, lobes oblong, 2–3 × 2.5–3.5 mm. Pistil 10–11 mm long, ovary narrowly ovoid, 3–4 mm long, ca. 1 mm across, sparsely puberulent; style 6–7 mm long, sparsely puberulent; stigma ca. 0.5–0.7 mm long, 0.5 mm wide. Capsule narrowly ellipsoidal, 7–8 mm long, 1–1.5 mm across, sparsely pubescent.
Distribution, habitat and ecology: Primulina pseudoglandulosa grows on moist shade cliffs of limestone, and also on moist rock face at the entrance of karst cave in Yangshuo, Guangxi (Fig. 5), at alt 120–150 m.
Phenology: Flowering from Jun to Jul, fruiting from Aug to Oct.
Notes: Because phylogenetic analyses show that Primulina glandulosa (Fig. 13a, b) and P. glandulosa var. yangshuoensis (Fig. 13c–g) are not closely related (Fig. 4a), it is inadequate to treat the latter a variety of the former. However, the existence of Primulina yangshuoensis Y.G.Wei & F.Wen blocks the direct transfer of P. glandulosa var. yangshuoensis to the specific status. The new name Primulina pseudoglandulosa (Fig. 13c–g) is proposed to highlight its morphological similarity to P. glandulosa (Fig. 13a, b).
Additional specimens examined: CHINA. Guangxi: Yangshuo County, Shenqiyan Cave, 5 Apr 2014, M.-Q. Han & J. Guo G017 (IBK); Yulonghe, 16 Jul 2015, K-.F. Chung et al. 3022 (HAST, IBK); Gaotian Town, 1 Sep 2010, L. Wu & W.-B. Xu 10960 (IBK); Fuli Town, 28 Jul 2009, W.-B. Xu et al. 09745 (IBK); ibid., 5 Sep 2012, W.-B. Xu 11884 (IBK).
Primulina subulata var. guilinensis (W.T.Wang) W.B.Xu & K.F.Chung, comb. nov.: Chiritopsis repanda var. guilinensis W.T.Wang, Guihaia 12(4): 299. 1992.—Primulina repanda var. guilinensis (W.T.Wang) Mich.Möller & A.Weber in Taxon 60(3): 784. 2011.—TYPE: CHINA, Guangxi, Guilin City, Jiangjunqiao, 11 Aug 1960, Y.-Y. Yang 6517 (holotype: PE!, isotype GXMI!). 桂林小花苣苔 (Fig. 10).
Description: Herbs perennial. Rhizome subterete, 2–8 cm long, 6–10 mm wide. Leaves 6–14, basal, petiolate, herbaceous; petiole flat, 2–10 cm long, 1.5–2.5 mm wide, pubescent; blades ovate, broadly ovate, elliptical, cordate, 4.0–12.5 × 2.5–6.5 cm, pubescent on both surfaces, base cuneate to cordate, margin repand to dentate, apex acute to obtuse; lateral veins 2–4 on each side. Cymes 2–6, axillary, 1–3-branched, 4–16-flowered; peduncle 3–16 cm long, ca. 1.5 mm in diam, pubescent; bracts 2, opposite, lanceolate, 6–8 × 2–2.5 mm, margin entire, pubescent; pedicel 4–21 mm long, pubescent. Calyx 5-parted to base, lobes lanceolate-linear, 5–7 × 0.8–1 mm, apex acuminate, outside pubescent, inside sparsely puberulent, margins entire. Corolla white, 8–14 mm long, outside sparsely pubescent, inside sparsely puberulent, with 2 vary pale purple stripes; corolla tube 6-10 mm long, 4.5–5.5 mm in diam. at the mouth, 3–4 mm in diam. at the base; limb distinctly 2-lipped; adaxial lip 2-parted to over the middle, lobes oblong, 1.5–2 × 2–3 mm; abaxial 3-lobed to over the middle, lobes oblong, 2.5–3.5 × 2.5–3.5 mm. Pistil 10-12 mm long, ovary narrowly ovoid, 3.5–4.5 mm long, ca. 1 mm across, puberulent; style 6–7 mm long, puberulent; stigma ca. 0.5–0.7 mm long, 0.5 mm wide. Capsule narrowly ellipsoidal, 5–6 mm long, 1–1.5 mm across, pubescent.
Distribution, habitat and ecology: Primulina subulata var. guilinensis grows on moist rock face at the entrance of karst cave, and also on moist shade cliffs of limestone, in Guangxi (Gongcheng, Guilin, Hezhou, Pingle, Quanzhou, Zhongshan) and Hunan (Jiangyong), at alt 100–230 m. The record of Chiritopsis repanda var. guilinensis in Luzhai County, Liuzhou City in Li and Wang (2004) is incorrect based on our field observation.
Phenology: Flowering from Jul to Aug, fruiting from Sep to Oct.
Notes: Phylogenetic analyses indicate that Primulina repanda var. guilinensis is placed in a strongly supported clade that also includes P. subulata and P. subulata var. yangchunensis, distantly related to P. repanda (Fig. 4). To better reflect its phylogenetic position, we propose to make the current nomenclatural change.
Additional specimens examined: CHINA. Guangxi: Guilin City, Qixing District, 18 Jul 2009, W.-B. Xu et al. 09774 (IBK, HAST). Quanzhou County, Shitang Town, 1 Aug 2014, Quanzhou Exped. 450324140801022 (IBK, GXMG). Gongcheng County, Xiling Town, 28 Aug 2006, W.-B. Xu & Y.-Y. Liang 06037 (IBK). Hezhou City, Babu District, 4 Oct 2008, W.-B. Xu & W.-H. Wu 08212 (IBK), ibid., 26 Jul 2009, W.-B. Xu et al. 09788 (IBK, HAST); Etang Town, 10 Jul 2009, Y. Liu & W.-B. Xu 091740 (IBK), ibid., 7 Aug 2012, W.-B. Xu et al. 11714 (IBK). Pingle County, Yuantou Town, 4 Apr 2014, M.-Q. Han & J. Guo G010 (IBK). Zhongshan County, Qingtang Town, 4 Apr 2014, M.-Q. Han & J. Guo G009 (IBK). Hunan: Jiangyong County, Lanxi Town, 25 Jun 2011, X.-L. Yu 110611 (CSFI); ibid., 9 Apr 2018, C.-R. Lin et al. YY190 (IBK).
Primulina bipinnatifida (W.T.Wang) Yin Z.Wang & J.M.Li in J. Syst. Evol. 49(1): 60. 2011.—Chiritopsis bipinnatifida W.T.Wang, Bull. Bot. Res., Harbin 1(3): 26. 26–28, pl. 1(9–11), pl. 4(1). 1981.—TYPE: CHINA, Guangxi, Lingui County, Huixian Town, Sishan, 29 Jun 1977, Lingui Exped. 6-1575 (holotype: GXMI!). 羽裂小花苣苔 (Figs. 3, 6, 7).
Chiritopsis lingchuanensis Yan Liu & Y.G.Wei in Acta Phytotax. Sin. 44(3): 340–343, Fig. 1. 2006.—Primulina lingchuanensis (Yan Liu & Y.G.Wei) Mich.Möller & A.Weber in Taxon 60(3): 783. 2011.—TYPE: CHINA, Guangxi, Lingchuan County, Dajing Town, alt 340 m, 11 Sep 2004, Y. Liu L1085 (holotype: IBK!, isotypes: IBK!, PE), syn. nov. (Fig. 3e–h).
Primulina jianghuaensis K.M.Liu & X.Z.Cai in Nord. J. Bot. 32(1): 70–73, Fig. 1 & 2. 2014.—TYPE: CHINA, Hunan Province, Jianghua County, 24°51′21.05″N, 111°42′58.22″E, at 397 m, 23 Jul 2012, K.M. Liu & X.Z. Cai 31269 (holotype: HNNU, isotypes: HNNU), syn. nov. (Fig. 3i–l).
Primulina cangwuensis X.Hong & F.Wen in Ann. Bot. Fennici 55(1–3): 38, Fig. 1 & 2. 2018.—TYPE: CHINA, Guangxi, Wuzhou City, Cangwu County, 23°50′N, 111°32′E, alt 200 m, 27 Sep 2010, HX 100907 (holotype: IBK!, isotype: ANU), syn. nov. (Fig. 3m–p).
Distribution: Primulina bipinnatifida is distributed in northeastern Guangxi (Cangwu, Guilin, Hezhou, Lingchuan, Lipu, Pingle, Xing’an, Yangshuo) and adjacent areas of Hunan Province (Jianghua) (Fig. 5).
Notes: Our field observations (Fig. 3, 7) and phylogenetic analyses (Fig. 4a) support to recognize P. bipinnatifida a morphologically variable species distributed in northeastern Guangxi and southern Hunan (Fig. 5). Despite its variable leaf shapes, the recircumscribed P. bipinnatifida is readily recognizable by the white variegation along the midveins and the secondary veins of the leaves (Fig. 3, 7). Population genetic and phylogeographic studies of P. bipinnatifida are currently underway to understand evolutionary mechanisms underlying this variable species.
Additional specimens examined: CHINA. Guangxi: Guilin City, Yanshan Town, 10 Oct 1950, J.X. Zhong 808581 (IBK). Lingui County, Huixian Town, Aug 2005, W.-B. Xu LG-001 (IBK); ibid., 1 May 2009, W.-B. Xu & Y. Liu 09409 (IBK), ibid., 28 Jul 2009, W.-B. Xu et al. 09741 & 09742 (IBK), ibid., 14 Jul 2015, K.-F. Chung et al. 2987 (HAST, IBK). Hezhou City, Kaishan Town, 8 Jul 2015, K.-F. Chung et al. 2922 (HAST, IBK). Lingchuan County, Dajing Town, 30 Aug 2006, W.-B. Xu 06039 (IBK), ibid., 6 Jul 2007, B. Pan & W.-B. Xu 07240 (IBK), ibid., 17 Jul 2015, K.-F. Chung et al. 3028 (HAST, IBK); Chaotian Town, 18 Jul 2009, W.-B. Xu et al. 09773 (IBK, HAST), ibid., 15 Jul 2015, K.-F. Chung et al. 2999 (HAST, IBK). Pingle County, Qiaoting Town, 27 Jul 2017, Pingle Exped. 450330170727076LY (IBK, GXMG); Tong’an Town, 9 Nov 2018, Pingle Exped. 450330181109001LY (IBK, GXMG). Yangshuo County, Putao Town, 1 Aug 2006, W.-B. Xu 06038 (IBK); Xingping Town, 28 Jul 2009, W.-B. Xu et al. 09797 (IBK, HAST), ibid., 16 Jul 2015, K.-F. Chung et al. 3013 (HAST, IBK); Baisha Town, 28 Jul 2009, W.-B. Xu et al. 09744 (IBK). Lipu County, Qingshan Town, 25 Aug 2006, W.-B. Xu & Y.-Y. Liang 06035 (IBK), ibid., 27 Jul 2009, W.-B. Xu et al. 09753 (IBK, HAST). Cangwu County, Shiqiao Town, 10 Jul 2009, Y. Liu & W.-B. Xu 091743 & 091744 (IBK); ibid., 26 Jul 2009, W.-B. Xu et al. 09789 (IBK, HAST). Xing’an County, Baishi Town, 15 Jul 2015, K.-F. Chung et al. 2998 (HAST, IBK). Hunan: Jianghua, Daxu Town, 8 Jul 2015, K.-F. Chung et al. 2925 (HAST, IBK); 9 Jul 2015, K.-F. Chung et al. 2932 (HAST, IBK).
Primulina bipinnatifida var. zhoui (F.Wen & Z.B.Xin) W.B.Xu & K.F.Chung, comb. & stat. nov.: Primulina zhoui F.Wen & Z.B.Xin in Taiwania 63(1): 54–56, fig. 1 & 2. 2018—TYPE: CHINA, Guangxi, Liuzhou City, Liujiang District, Liyong Town, 24°13′N, 109°28′E, Alt. 117 m, 18 Jul. 2015, F. Wen et al. WF150718-01 (holotype IBK!; isotypes IBK, KUN, PE, TAI!). 周氏小花苣苔 (Fig. 3q, r).
Notes: Because of the disjunct distribution in central Guangxi and its unique leaf shape, Primulina zhoui is treated as a variety under P. bipinnatifida.