Meistera muriformis Škorničk., 2023

Leong-Škorničková, Jana, Bình, Nguyén Qu ốc, Đăng, Tr ần H ữu, Záveská, Eliška, Quang, Bùi H ồng, Bình, Tr ần Đ ức, Ye, Xing-Er, Nguyen, Khang Sinh, Kuznetsov, Andrey N., Kuznetsova, Svetlana P. & Nuraliev, Maxim S., 2023, A key to Meistera (Zingiberaceae: Alpinioideae) in Cambodia, Laos and Vietnam, with a description of a new species, M. muriformis, Phytotaxa 618 (2), pp. 149-160 : 152-154

Meistera muriformis Škorničk. , sp. nov. ( Figs. 1–4 )

Diagnosis: —Similar to Meistera stephanocolea in general plant size and habit, pubescent to hirsute ligules, coloration of flowers, and echinate fruits, but differs by prominently reticulate to muriform (vs striate to finely reticulate) leaf sheaths, shortly petiolate (vs sessile) leaf blades, labellum predominantly white with small yellow patch in the centre and hint of pink tinge on the both sides of the yellow patch (vs labellum white with broad central yellow stripe, edged with red dots and two lines of red dots radiating to margin), anther crest semi-circular to bluntly squared to oblong (vs prominently trilobed).

Type: — VIETNAM. Kon Tum Province: Kon Plong District, Xa Hieu , N 14°38’56.5” E 108°25’03.1”, c. 1222 m a.s.l., 24 April 2012, J. Leong-Škorničková, Q. B. Nguy ễn, H. Đ. Trǻn, E. Záveská JLS-1556 (holotype: SING: SING0291158 ! [including inflorescences and flowers preserved in spirit as a part of a single specimen], isotypes: E!, PR!, VNMN! [including inflorescences and flowers preserved in spirit as a part of a single specimen]) .

Rhizomatous herb 1.0– 1.8 m tall, clump-forming, with 2–15 pseudostems per clump, pseudostems 8–13 cm apart, slightly swollen at base; stilt roots absent. Leafy shoot composed of 5–23 leaves per pseudostem, bladeless in basal 1/3 to 1/2; bladeless sheaths 3–5; basalmost bladeless sheaths cream to pinkish basally, green towards apex, rest of the sheaths green; leaf sheaths green, prominently reticulate to muriform, margin densely pubescent (especially distally towards the ligule), otherwise pubescent to sparsely pubescent, glabrescent with age; ligule bilobed (lobes more obscure in uppermost leaves), to c. 5 mm long, outside (abaxially) green to dark red and covered by dense brown hairs throughout, inside (adaxially) green to dark red, glabrous; petiole to 5 mm long, green, densely pubescent to puberulent; leaf blade elliptic, smooth, 14.5–32.0 × 5.0–9.0 cm, adaxially green to dark green, somewhat shiny, glabrous, abaxially lighter green, pubescent, base rounded to obtuse, slightly oblique, apex acuminate, shortly caudate, cauda c. 1 cm long. Inflorescence radical, 1–2 inflorescences per shoot; peduncle to 20 cm long, covered by sheathing scales; scales cream at base (part embedded in soil or covered with leaf litter), distally green with reddish tinge or dark red, coriaceous, adaxially glabrous, abaxially densely puberulent, apex shortly mucronate; flowering part (raceme) ovoid, 4–7 cm long, c. 4 cm in diam., with 1–3 flowers open at the same time; fertile bracts numerous (approx. 30–50), shallowly boat-shaped, narrowly elliptic, dry brown or completely decayed at anthesis (visible only in budding inflorescence), acute at apex, with entire margin, each subtending one flower; bracteoles presumably tubular (completely decayed at anthesis). Flower of open type, 3.5–4.5 cm long including pedicel; pedicel to 7 mm long (extending to 15 mm in fruiting stage), pinkish, tomentose to puberulent; calyx tubular, 1.4–1.6 cm long, reddish to dark red at base, gradually turning semitranslucent white to greenish distally, mostly glabrous, sparsely pubescent towards base, apex tridentate with teeth 3–4 mm long, tooth apex acute with a small mucro; floral tube c. 2 cm long, white externally and internally, externally sparsely pubescent, internally glabrous at base, villose towards throat; dorsal corolla lobe elliptic, 1.2–1.5 × 0.5–0.7 cm, white, glabrous, apex cucullate; lateral corolla lobes ovate to elliptic, 1.1–1.3 × 0.4–0.6 cm, white, glabrous; labellum obovate with emarginate apex, obscurely clawed at base, 1.5–1.7 × 1.4–1.6 cm, white with yellow central patch bordered with faint pinkish tinge at base, adaxially densely pubescent at basal half, abaxially glabrous; lateral staminodes sharply triangular or subulate, to 3 mm long, sometimes inconspicuous and tooth-like, white with bright red tinge, pubescent at base; stamen 1.2–1.4 cm long; filament flat, 5–6.5 × 2–2.5 mm, white, adaxially puberulous, abaxially mostly glabrous, but with few sparse hairs; anther oblong, 7–9 mm long (including crest), 2–3 mm wide (thecae part, narrower basally), connective tissue white, glabrous to sparsely puberulent (glandular hair); anther thecae 6 mm long, dehiscing throughout entire length; anther crest semi-circular to bluntly squared to oblong, entire, sometimes with irregularly shaped margin, 1.5–2.5 mm long, 2–2.5 mm wide, white, glabrous; pollen grains sphaerical, white to cream white. Ovary cylindrical or subcylindrical, 3–4 × 2 mm, cream-coloured, tomentose, hairs white to pale golden; epigynous glands two, irregularly cylindrical, 2–3.5 mm long, yellow-green, glabrous, apex blunt to truncate; style filiform (thicker in apical 3–5 mm), white, mostly glabrous, sparsely pubescent distally, more densely pubescent in apical 3–5 mm; stigma dorso-ventrally flattened, funnel-shaped, c. 1.5 × 1.5 mm, white; ostiole ciliate, facing upwards. Fruit a spiny (echinate) hesperidium, globose to sub-globose, c. 2 cm in diam., red, tomentose; spines fleshy, unbranched, 2–3 mm long, with long hair; seeds irregularly bluntly angular to semi-globular, 3–4 mm in diam., dark brown, surrounded by white juicy aril.

Etymology: —The specific epithet refers to the prominently sculptured leaf sheaths, which resemble the brick walls.

Vernacular names and uses: —No vernacular names or uses have been recorded.

Ecology & phenology: — Meistera muriformis occurs in primary evergreen broad-leaved and mixed montane forests, sometimes near streams, but has also been seen in disturbed evergreen broad-leaved montane forest along roadside, at elevations of 865–1223 m a.s.l. Flowers in March–May, fruits in April–December. The species exhibits flexistyly, a floral dimorphism unique to Zingiberaceae with two flower morphs differing in the direction of stigma movement during the day, facilitating outcrossing ( Li et al. 2001).

Distribution & IUCN preliminary assessment: — Meistera muriformis is recorded in two neighbouring provinces of Vietnam: Kon Tum (Kon Plong District) and Gia Lai (K’Bang District, Kon Chu Rang Nature Reserve). The species is thus endemic to the Kon Tum — Gia Lai Plateau, which is sometimes considered to be a part of the so-called ‘Tay Nguyen Plateau’ (see e.g. Poyarkov et al. 2021). Meistera muriformis has a small estimated Extent of Occurrence (EOO) (c. 243 km 2), and the Area of Occurrence (AOO) is 32 km 2 (assessed using GeoCAT: Bachman et al. 2011). It is represented by nine currently known records (eight documented by herbarium specimens, one as a photographic record). The three records from Kon Tum were made in the area that is not legally protected and suffers from forest clearance, but the other six records originate from the legally protected forest of Kon Chu Rang Nature Reserve. From the cited records it is evident that in Kon Chu Rang Nature Reserve the species is rather common. We therefore propose to treat this species as ‘Least Concern’ (LC), following the guidelines of the IUCN Standard and Petitions Subcommittee (2022).

Additional specimens examined (paratypes):— VIETNAM. Kon Tum: Kon Plong District , Xa Hieu, N 14°40’55.3” E 108°23’08.3”, c. 1223 m a.s.l., 26 April 2012, J. Leong-Škorničková, Q. B. Nguy ễn, H.Đ. Trǻn, E. Záveská JLS-1586 [fl.] ( SING: SING0291159 , VNMN) ; Gia Lai: K’Bang District, Son Lang Municipality, Kon Chu Rang Nature Reserve , 32 km ESE of Mang Den Town, N 14°27’49’’ E 108°35’12’’, elev. 940 m, 1 April 2018, M. S. Nuraliev, A. N. Kuznetsov, S. P. Kuznetsova 1963 [fl.] ( MW: MW0757541 ; SING: SING0388901 ) ; ibidem, 29 km ESE of Mang Den Town , N 14°29’53’’ E 108°32’46’’, elev. 1000 m, 24 May 2016, M. S. Nuraliev 1539 [fl.] ( MW: MW0754355 , SING: SING0388902 ) ; Kon Chu Rang Nature Reserve , N 14°28’29.3’’ E 108°32’18.3’’, elev. 865 m, 22 April 2022, B. H. Quang, T.D. Binh, V. A. Thuong, D. T. Hoan, D. V. Hai, N. T. Cuong, T. N. Minh BHQ 512 [fl.] ( HN, the herbarium of Kon Chu Rang Nature Reserve ) ; ibidem, N 14°27’35.6’’ E 108°31’58.5’’, elev. 998 m, 22 April 2022, B. H. Quang, T.D. Binh, V. A. Thuong, D. T. Hoan, D. V. Hai, N. T. Cuong, T. N. Minh BHQ 614 [fl. & fr.] ( HN, the herbarium of Kon Chu Rang Nature Reserve ) ; ibidem, N 14°28’20.3’’ E 108°32’53.1’’, elev. 1016 m, 24 April 2022, B. H. Quang, T.D. Binh, V. A. Thuong, D. T. Hoan, D. V. Hai, N. T. Cuong, T. N. Minh BHQ 810 [fl.] ( HN, the herbarium of Kon Chu Rang Nature Reserve ) ; ibidem, N 14°28’48.9’’ E 108°32’58.0’’, elev. 997 m, 20 December 2022, B. H. Quang, T.D. Binh BHQ 895 [fr.] ( HN).

Other field records:— VIETNAM. Kon Tum: Kon Plong District, Mang Canh Municipality, Thach Nham Protected Forest , 13 km NNE of Mang Den Town, forest, near river, N 14°42’40’’ E 108°19’00’’, elev. 1050 m, 16 April 2015, M. S . Nuraliev 1373a [fl.] (photo record, LE: LE01093258 ) .

Notes: —Of the 14 species of Meistera previously known in Cambodia, Laos and Vietnam, 11 species occur in Vietnam, and only two species are widespread in all three countries ( Table 1 ). Of these 14 species, M. koenigii and M. tomrey are distinct from the new species in having smooth fruits, and M. cristatissima , M. sudae , M. verrucosa and M. vespertilio have entirely yellow flowers ornamented with red. Of the remaining eight species, only M. stephanocolea is morphologically similar to M. muriformis , although it can be readily distinguished by the characters outlined in the diagnosis. Meistera stephanocolea is so far known only from three collections, all made in a single location in Bolikhamsai Province in Laos, which is distanced well over 600 km (air distance) from the locations of M. muriformis . The two species also show very different ecological preferences, with M. muriformis being a mid-elevation species occurring in evergreen broad-leaved and mixed montane forests at elevations of around 850–1250 m, whereas M. stephanocolea occurs in evergreen dry lowland forests and deciduous mixed forests, at elevations of 120– 238 m.

Meistera muriformis is also distinct from all other species in the genus. One of the most remarkable characteristics of M. muriformis is the reticulate to muriform leaf sheath. Reticulate leaf sheath occurs also in M. chinensis , one of the two most widespread Meistera species across Cambodia, China, Laos and Vietnam. Nevertheless, M. muriformis can be easily differentiated from M. chinensis by ligule covered throughout by dense brown hairs (vs glabrous ligule), open (vs gullet-type) flowers and entire (vs trilobed) anther crest (for M. chinensis , see Figure 13.11 in Leong-Škorničková & Newman 2015 and Figure 7A, E & I in De Boer et al. 2018).

The anther crests in Meistera species are mainly semilunar-entire or semilunar trilobed, only very rarely the crest is smaller and less prominent, i.e. short and entire ( De Boer et al. 2018), as seen, apart from M. muriformis , for example in M. lappacea ( Ridley 1899: 134) Škorničk. & M.F.Newman in De Boer et al. (2018: 26) from Peninsular Malaysia. As in M. muriformis , the flowers in M. lappacea are of an open type, although the labellum is entirely yellow. Similarities in flower morphology of these two species can perhaps be attributed to adaptation to a similar pollinator.

Figures

FIGURE 1. Meistera muriformis. A. Young leafy shoot. B. Base of pseudostem with inflorescences. C. Portion of pseudostem showing leaf sheaths and ligules. D, E. Flower in semi-side and front views. F. Flower and flower dissection (from left to right): Flower including pedicel in side view, flower with labellum and corolla lobes removed, corolla lobes and labellum (dorsal corolla lobe in the middle), calyx. G. Pedicel with ovary and epigynous glands, stamen with staminodes and upper part of the floral tube in adaxial, side & abaxial views. Photos by Jana Leong-Škorničková; all based on the type, Leong-Škorničková et al. JLS-1556.

FIGURE 2. Meistera muriformis. A. Mature leafy shoot. B, C. Detail of ligule. D. Inflorescence (top view). E. Rhizome with base of leafy shoot and two inflorescences. F. Budding inflorescence with insets showing stamens in adaxial view. Photos by Maxim Nuraliev; A–C, F lower inset based on Nuraliev et al. 1539; D–F inclusive upper inset based on Nuraliev et al. 1963.

FIGURE 3. Meistera muriformis. A. Mature leafy shoot. B. Inflorescence (top view). C. Rhizome with base of leafy shoot and inflorescences. D. Inflorescence (flowers in side view). E. Infructescence with single young fruit (inset: detail of the spines, from fixed material). Photos by Bui Hong Quang; A, D based on Quang et al. BHQ 512; B, C, E based on Quang et al. BHQ 614.

FIGURE 4. Distribution of Meistera murifomis and Meistera stephanocolea.