Geostachys annamensis Ridl.

Leong-Škorničková, Jana, Bình, Nguyén Qu ốc, Đăng, Tr ần H ữu, Trư ờng, Lưu H ồng & Nuraliev, Maxim S., 2023, A revision of Geostachys (Zingiberaceae: Alpinioideae) in Cambodia, Laos and Vietnam, including a new species, G. aristata, Phytotaxa 585 (4), pp. 245-260 : 246-250

Geostachys annamensis Ridl. in Baker et al. (1921: 122) ( Fig. 1 , 2 )

Lectotype (designated here): —[ VIETNAM: Lâm Đồng province]: Dalat , 5000 ft [ca. 1500 m], April & May 1918, C. Boden Kloss s.n. ( BM: BM000617532 !, flowering).

Clump-forming herb up to 1.6 m tall. Rhizome supported by stilt roots, sheathed by dry brown scales. Leafy shoots with 8–16 leaves per pseudostem, bladeless at basal 1/3; bladeless sheaths 4–6, most basal (outermost) sheaths very short, dry and brown, inner sheaths distally gradually longer, finely ribbed, green with dark red tinge and dark red reticulate pattern, pubescent to glabrous (variable between populations); leaf sheaths finely ribbed, green with dark red reticulate pattern and often with red tinge more prominent towards margin, pubescent to glabrous (variable between populations); ligule 3–5 mm long, with round to shallowly bluntly bilobed apex, red to dark red, base glabrous, margin pubescent (glabrescent with age); petiole 1–7 mm long, shallowly canaliculate, green to red, adaxially glabrous or nearly so, abaxially pubescent to glabrous; leaf blade narrowly oblong, 25–45 cm long, 3–5 cm wide, adaxially green to dark green, more or less hirsute to glabrous (rarely), abaxially paler green, rarely with dark reddish shading near margins, densely hirsute to glabrous (rarely), base obtuse, apex prominently acuminate, midrib adaxially sunken, green or red, shortly hirsute to glabrous, abaxially protruding, green or with dull red tinge, hirsute to glabrous. Inflorescence radical, erect; peduncle to 18 cm long, covered by 8–12 sheathing bracts; sheathing bracts distichous, broadly to narrowly ovate, overlapping, basal ones shorter and tightly appressed to the peduncle, distal 4–6 significantly larger and somewhat puffed, richly tinged red, soon becoming brown and papery, adaxially glabrous, abaxially shortly pubescent to glabrous; thyrse lax, many-flowered; rachis 10–18 cm long, green to ochraceous, sometimes with reddish tinge, hirsute, shortly branched; bracts broadly ovate to broadly elliptic with round apex, shallowly bowl-shaped, somewhat crumpled, 4–16 mm long, ca. 5–18 mm wide when flattened, semi-translucent white to white, often with more or less dense pink tinge, glabrous, each subtending cincinnus of 2–5 flowers on 2–5 mm long branch; branches evenly distributed around rachis, of the same colour and indumentum as rachis; bracteoles broadly ovate to broadly elliptic with round apex, shallowly bowl-shaped, somewhat crumpled, 3–15 mm long, 6–17 mm wide when flattened, semitranslucent white, often with more or less dense pink tinge, glabrous. Flower 4–5 cm long, gullet-type; pedicel 2–6 mm long, pale green to cream, often with pink to red tinge, sparsely puberulous; calyx tubular, 8–9 mm long, with dorsal unilateral incision ca. 4–5 mm from apex, apex obscurely 3-lobed, lobes round (very rarely bluntly mucronate) at apex, less than 1 mm long, white with translucent margins, lobes often tinged pink, glabrous; floral tube 18–20 mm long, externally white to pale pink, glabrous; dorsal corolla lobe broadly ovate to nearly round with mucronate apex, ca. 18 mm long (including ca. 2 mm long mucro), ca. 19 mm wide, white or with very slight pink tinge and semi-translucent to translucent margins, glabrous; lateral corolla lobes broadly elliptic-ovate with obtuse apex, ca. 18 mm long, ca. 11 mm wide, white with translucent margins, glabrous; labellum obovate with crenulate obscurely bilobed apex, 28–33 mm long, 25–30 mm wide (40–45 mm wide if inclusive of staminodes), white with dark pink or pink-red spots and larger linear blotches in the central part, but not extending to the wide white margins, adaxially with white glandular hair in the centre, abaxially glabrous; lateral staminodes irregularly obovate, ca. 18 mm long, ca. 14 mm wide, connate to labellum in basal 3/4–4/5, white with dark pink or pink-red spots and blotches extending near to margins; stamen ca. 17 mm long (including crest); filament ca. 7 mm long, 2.5–3 mm wide, dorso-ventrally compressed, white with dark pink to red spots/blotches, with glandular hair; anther 10–12 mm long (including crest); connective yellow-green with red spots/blotches, with short glandular hair; crest 2–3 mm long, semi-circular with irregular lobes and crenulate margin, white to pale yellow with deep pink to red spots/blotches, glabrous; anther thecae 6–8 mm long, dehiscing through the entire length; ovary trilocular with central placentation, obovoid to ellipsoid, 3–4 mm long, 3–3.5 mm in diam., pale green to pale pink, glabrous; epigynous glands two, ca. 2 mm long, enveloping the base of style, ochraceous; style white to pink at base, turning darker pink distally, glabrous at base, sparsely puberulous distally; stigma capitulate, deep pink to red; ostiole transverse, forward-facing, ciliate. Fruit globose to subglobose hesperidium, 10–15 mm in diam. (when slightly immature), pale green, glabrous, with persistent calyx; seeds (immature) ca. 3 mm long, each fully enclosed in white aril (presumably semi-translucent white and juicy upon ripening).

Etymology:— The specific epithet refers to the occurrence of the species in the Annam protectorate of the former French Indochina.

Distribution & IUCN preliminary assessment:— Endemic to Vietnam. Geostachys annamensis is currently assessed as Data Deficient on IUCN Red List ( Olander 2019a).The assessment was carried based on only two collections, of which one is a type of G. annamensis , but the second represents G. aristata . Based on more comprehensive data presented here, we therefore suggest re-assessment of this species.The vast majority of collections are known from Lâm Đồng province (Ðà Lạt and vicinity, and also Bảo Lộc area), with two records from Đắk Lắk province and two records (inclusive of one photo-documented sighting) from Khánh Hòa province. GPS locations exist or could be assigned to seven collections, based on which we have calculated EOO as 3,585 km 2, and AOO as 8 km 2. Although exact numbers about various populations are not available, at least some of the populations are known to occur in legally protected areas, i.e., ChƯ Yang Sin National Park and Hòn Bà Nature Reserve. However, majority of the collection records come from the general area around Ðà Lạt which greatly suffered, and continues to suffer, from forest clearing for agriculture use. As this species can only grow in undisturbed primary forest, and there is a steep decline in extent and quality of this habitat, we suggest treating this species as Near Threatened (NT).

Ecology & phenology:— Growing in the understorey of evergreen broadleaved montane forests, at elevations of 800–1500 m a.s.l. Flowering from March to July, fruiting from May to August.

Additional specimens examined:— VIETNAM. Đắk Lắk province: Ea Kar district, ChƯ Yang Sin National Park , 12.4037868°N 108.4729321°E, 1193 m, 11 July 2018, H.T. Luu, H.Đ. Trǻn, M.T. Đặng, B.T. Lê, Q.D. Đinh & T.T. Nguyễn Tran- 743 ( SGN, flowering & early fruiting); L ắk district, Bông Krang municipality, ChƯ Yang Sin National Park , 12°23’49”N 108°20’59”E, elev. 1077 m, 27 May 2019, S.V. Yudina & M.S. Nuraliev YUD 17 ( MW: MW0758393 , MW0758394 , flowering). Khánh Hòa province: Cam Lâm district , Hòn Bà Nature Reserve , 12.0153°N 109.0099°E, 971 m, 18 August 2017, H.Đ. Trǻn, G. Trǻn, T.V. Nguyễn & T.M.H. Nguyễn KH2-107 ( SGN, old infructescences). Lâm Đỗng province: Lạc DƯõng district, Suối Vàng , 2 May 1980, N.T. Nhan 785 ( HN, flowering); ibidem, 2 May 1980, L.K. Biên 1228 ( HN, flowering); ibidem, 3 May 1980, N.V. Tṵ 82 ( HN, flowering); Ðam Rông district, Phi Liêng , 11.9976886°N 108.1126386°E, 1000 m, 20 May 2018, H.Ð. Trǻn, H.T. Luu & D. Lê Tran- 610 ( SGN, flowering & early fruiting); Dalat [Ðà Lạt], Dua Tria , dense forest, 1450 m, 10 April 1953, M. Schmid VN1644 ( P: P00599390 , flowering); Dalat [Ðà Lạt], 7 km south of Dalat, Haut Donai , 1400 m, 23 March 1935, E. Poilane 24815 ( P: P06136202 , flowering); Dalat? [Ðà Lạt], Lò Hung region , forest, 950 m, 27 March 1953, M. Schmid VN1646 ( P: P00599389 , flowering); [Đà Lạt], Manline , 21 April 1957, P. Tixier 21/4/57 -02 ( P: P02203167 , flowering); Đức Trọng district, Núi Voi , 6 May 2016, Q.Ð.Nguyễn & H.T. Luu LBA006 ( SGN, flowering); Di Linh district, Đinh Trang ThƯỢng , 16 May 1980, Hà Tuḗ 458 ( HN, fruiting); Bảo Lâm district, Lộc Bắc municipality, 12 km WNW of Lộc Thắng town, forest, 11°43’30”N 107°42’55”E, elev. 1050 m, 6 April 2013, M.S. Nuraliev, A.N. Kuznetsov, & S.P. Kuznetsova 775 ( MW: MW0749958 , SING: SING0215785 , flowering) .

Other field records:— VIETNAM. Khánh Hòa province: Cam Lâm district, Hòn Bà Nature Reserve , 12°06’46.3”N 108°58’27.1”E, ca. 900 m, 4 July 2011, J. Leong-Škorničková et al. JLS-3817 (fruiting, photo uploaded to LE: LE01093253 ) .

Nomenclatural notes: —Ridley (in Baker et al. 1921) described Geostachys annamensis in a volume dedicated to the collections by C. Boden Kloss. The protologue of this species states the locality as “Dalat, 5,000 ft ” and does not cite any collections.

Turner (2000), who dealt with typifications of Zingiberales names published by H.N. Ridley, stated that he could not trace any type material of this species. However, at least one relevant specimen collected by Boden Kloss exists in BM. The original label matches the protologue in all aspects, and the specimen also bears determination slip in Ridley’s hand ( van Steenis-Kruseman & van Steenis, 1950) ‘ Geostachys annamensis Ridl. ; H.N.Ridley’.Although this sheet may well be the holotype, it cannot be excluded with certainty that more duplicates of this collection, as well as other collections by Boden Kloss from the same location, exist. This sheet is therefore designated here as the lectotype, in line with recommendation by McNeil (2014).

Taxonomic notes: —Although the original description is rather brief, Ridley (in Baker et al. 1921) noted that the leaf sheaths are spotted with red (the red reticulation and dark ligule are seen well even in the lectotype specimen), and he also included a note by Boden Kloss that the flowers are white tinged with pink and spotted with crimson. Several recent collections accompanied by photographic documentation made in Bảo Lộc area, Lâm Đồng province (Nuraliev et al. 775) and ChƯ Yang Sin National Park, Đắk Lắk province (Luu et al. Tran-743, Yudina & Nuraliev YUD 17) (air distance approximately 70 km southwest and 50 km north of the type locality, respectively), as well as sighting of fruiting individuals in Hòn Bà Nature Reserve , Khánh Hòa province (Leong-Škorničková et al. JLS-3817; air distance approximately 50 km southeast of the type locality) are consistent with Ridley’s description as well as with the lectotype, making the identity of the species clear ( Fig. 2 ).

Nguyễn (2017) listed three additional Vietnamese collections under G. annamensis whose identifications remained preliminary as they were based solely on the herbarium material that does not show important features of floral structure. For two collections from Thừa Thiên Huḗ province, Averyanov et al. HAL 7236 & HAL 7896, photographic material is available, and allows both to be assigned to Amomum Roxburgh (1820: 75) , another genus of Zingiberaceae . The third collection, N.Q. Bình 576 from Gia Lai province, cannot be identified with confidence.

Figures

FIGURE 1. Distribution map of Geostachys species in Cambodia, Laos and Vietnam.

FIGURE 2. Geostachys annamensis. A. Habit. B. Detail of leaf sheath and ligule. C. Inflorescence (side view). D & E. Flower (front view). F. Flower (side view). G. Detail of 3-flowered cincinnus; note the young fruit with persistent calyx. H. Stamen attached to floral tube (adaxial view). All from Nuraliev et al. 775. Photo by M. Nuraliev.