Mimulicalyx rosulatus Tsoong (1979: 400)

Zhao, Fei, Min, Dao-Zhang, Xiang, Chun-Lei, Chen, Bin, Zhou, Xin-Xin, Liu, Bing & Li, Bo, 2021, Morphological evidence for the conspecific status of the rediscovered Mimulicalyx rosulatus and M. paludigenus, Phytotaxa 520 (1), pp. 106-112 : 109-111

Mimulicalyx rosulatus Tsoong (1979: 400) . Figs. 1 , 3 , 4

Type:— CHINA. Yunnan Province: Jianshui County, Yangjieba Village , marshes, 15 March 1941, T. N . Liou 18265 [Holotype: PE! (barcode no. 0031326); isotypes: IBSC! (barcodes no. IBSC0004765 , IBSC0004766 )] .

Mimulicalyx paludigenus Tsoong (1979: 400) in Jin & Chen (1994: 613), syn. nov. ≡ Mimulicalyx paludigenus Tsoong in Li & Cai (2005: 319), isonym ≡ Mimulicalyx paludigenus Tsoong in Lin et al. (2009: 574), isonym. Type:— CHINA. Yunnan Province: Mengzi City, Shau-shin-jay (Xiaoxinzhai Village), bare grassy slope, Alt. 1400 m, 5 September 1939, C.W. Wang 81476 [Holotype: PE! (barcode no. 00031416); isotype: IBSC! (barcode no.0573074)].

Description: —Herbs perennial. Primary roots obvious or not; lateral roots well developed, fibrous, fascicled, white and slightly freshy. Stems quadrangular, slightly winged, glabrous, much branched at the base, 5–45 cm tall, erect or basally somewhat prostrate. Leaves opposite, sessile, mostly basal in dry habitat or dominantly cauline in wet habitat; leaf blade narrowly spatulate, spatulate-oblanceolate to broadly lanceolate, 2.2–5.5 × 0.4–1.2 cm, base narrowly cuneate to rounded, somewhat amplexicaul, margin subentire with few inconspicuous teeth, apex obtuse; cauline leaves decreasing in size upward. Flowers solitary, axillary in upper leaf axils, forming a racemose inflorescence, up to 20 cm long; bracteoles absent. Pedicels thin, slender, 1.8–3.5 cm long. Calyx campanulate, 3.5–5.5 mm long, 5 main veins, angled to winged-angled; apex 5-toothed, lobes triangular, 1/4 to 1/3 length of tube, recurved. Corolla funnelform, sagittally compressed, white to pale purple with pink stripes, 1.2–1.5 cm; tube long, subcylindric; palate with yellow spots and 2 bulging plaits, densely villous; limbs strongly bilabiate, margins minutely ciliate; upper lips erect, 2- lobed, lobes suborbicular; lower lips 3-lobed, lobes oblong to suborbicular, subequal, middle lobes emarginate, lateral lobes exserted in bud, as long as lobes of upper lip at anthesis. Stamens 4, included, didynamous; filaments glabrous; anthers white, 2-celled, locules basally divaricate, apically confluent. Ovaries oblong, 2-locular; placentation axile; style sparsely pubescent; stigmas bilamellate. Capsules oblong, compressed, emarginate, 6–9 mm long, loculicidal. Seeds numerous, brown, ellipsoid, with a transparent membrane.

Illustrations: —Tsoong (1979: 211, Fig. 57); Wu & Peter (1998: 81, Fig. 81); Wu (2006: 420, Plate 119).

Phenology:—Flowering from May to late September; fruiting from late May to October.

Distribution and habitat:— Mimulicalyx rosulatus is endemic to southwest China, and has been collected from southeast (Jianshui County, Mengzi City and Yanshan County) and northwest (Yongsheng County) Yunnan and southwest (Huidong County, Miyi County and Puge County) Sichuan ( Fig. 2 ). According to the collection information and our field experiences, the species commonly occurs in the wet habitat, such as roadside marshes along rice fields, swamps near streams, grassy lands of mountain slopes, and lake banks, from an altitude of 1100 to 1600 m.

Additional specimens examined: — CHINA. Yunnan Province: Honghe Hani and Yi Autonomous Prefecture, Jianshui County, NanzhuangTown, Yangjie Village , roadside grassland, along rice fields, 102°53′38″ N, 23°42′36″ E, Alt. 1530 m, 30 August 2020, X. B . Guo 20200830 [ JXAU! (barcode no. LB1079 ), CSH!]; Wenshan Zhuang and Miao Autonomous Prefecture , Yanshan County, Shih-tze-shan ( Shizishan Mountain ), swampy lands, Alt. 1200 m, 9 October 1939, C. W . Wang 84255 [ PE! ((barcode no. 02013806); IBSC! (barcode no. 0573075)]; Lijiang City, Yongsheng County, on the east bank of Chenghai Lake , grassy lands, 1 June 1976, Expedition of water and land conservation 112 ( KUN! (barcode no. 0379787)]; Sichuan Province: Liangshan Yi Autonomous Prefecture, Puge County, on the way to the Ningnan County , hillside, Alt. 1350−1420 m, 5 May 1957, Z. T. Guan 8110 [ KUN! (barcode no. 0379788)]; Huidong County , hillside across the county, swamp lands, Alt. 1520 m, 4 August 1961, T. L. Dai & S. P. Tang 11792 [ PE! (barcode no. 02013807)]; Panzhihua City , Miyi County , Gubing Town , roadside of rice fields, Alt. 1100 m, 10 July 1963, Miyi Expedition 0126 [ PE! (barcode no. 02013805)]; Caochang Town , Heping Village , roadside marshs, 102°03′43″ N, 26°57′14″ E, Alt. 1470 m, 9 May 2020, X.X. Zhou et al. ZXX20209999 [ JXAU! (barcode no. LB1063 ), CSH!].

Taxonomic note:—In the protologue of M. paludigenus, Tsoong (1979) simultaneously listed two gatherings as flowering (C.W. Wang 81476) and fruiting (C.W. Wang 84255) types, respectively, making the name invalid according to the Art. 40 of the International Code of Nomenclature for algae, fungi and plants (Shenzhen Code) ( Turland et al. 2018). The name was subsequently validated by Jin & Chen (1994) in their book A Catalogue of Type Specimens (Cormophyta) in the Herbaria of China where the gathering C.W. Wang 81476 deposited at PE was designated as the type. However, Li & Cai (2005) and Lin et al. (2009) did not notice the validation of the name and repeatedly validated the name, thereby producing two later isonyms as indicated in the Art. 6 Note 2 of the Shenzhen Code ( Turland et al. 2018).

Figures

FIGURE 1. Holotypes of Mimulicalyx rosulatus (A, T.N. Liow 18265, barcode no. 0031326 at PE) and M. paludigenus (B, C.W. Wang 81476, barcode no. 00031416 at PE). With the permission from the herbarium of the Institute of Botany, Chinese Academy of Sciences (PE).

FIGURE 2. Distribution map of Mimulicalyx rosulatus (red circle) and M. paludigenus (blue circles) with the rediscovered populations marked by yellow pentagons.

FIGURE 3. Individuals of Mimulicalyx paludigenus (A–G) and M. rosulatus (H–J) rediscovered from Miyi County of Sichuan Province and Jianshui County of Yunnan Province, respectively. A–D, H, I. Habit; E–G, J. Roots.

FIGURE 4. Morphological comparisons between Mimulicalyx paludigenus (A, left, B, left, C, E) and M. rosulatus (A, right, B, right, D, F). A. Transplanted individuals; B. Flowers; C, D. Pollens; E, F. Seeds. Scale bars: C, D = 2 μm; E, F = 40 μm.