Dactylostalix uniflora (Finet) Suetsugu

Suetsugu, Kenji, Yagame, Takahiro, Yukawa, Tomohisa & Suyama, Yoshihisa, 2024, Taxonomic revision of the formerly monotypic orchid genus Dactylostalix, Phytotaxa 652 (2), pp. 83-99 : 96-98

Dactylostalix uniflora (Finet) Suetsugu , comb. nov. ( Figs. 1D–F , 3–4 , 8 & 12 )

Basionym: Pergamena uniflora Finet (1900: 263)

Type:— JAPAN. Tohoku District— Forêts de l’Hayashinie, à partir de 1500 métres (= Iwate Pref.: Miyako-shi , Mt. Hayachine ), 14 June 1894, Faurie U.J., 13179 (lectotype: P00420868!; isolectotypes: P00420869!, K000943526! & KYO00090434!), designated here .

Rhizome creeping, pale brown. Scape arising from the rhizome, erect, 8–22 cm long, 1.0– 1.5 mm in diameter at the middle, glabrous, pale green, bearing one flower at the apex. Leaf solitary; leaf blade elliptic to ovate, 35–60 × 15–29 mm, pale green, obtuse at the apex, rounded or obtuse at the base; petiole broadly winged, 8–21 mm long. Bract 1.4– 2.5 mm long, pale green. Ovary and pedicel 6.0– 9.2 mm long, pale green. Dorsal sepal oblanceolate to oblong, 15–27 × 2.1–4.0 mm, yellowish-green, apex obtuse or acute. Lateral sepals obliquely oblong to falcate, 13–25 × 1.5–3.1 mm, yellowish-green, apex obtuse or acute. Lateral petals oblanceolate to oblong, 13–25 × 2.2–3.7 mm, yellowish-green, apex obtuse or acute. Labellum protruding, slightly reflexed at the apex, indistinctly 3-lobed, 11.6–21 × 4.0– 9.7 mm, disc with 2 distinct keels from the base to the middle, slightly divergent apically; lateral lobes narrowly triangular to ovate, 3.0–6.8 × 0.4–2.0 mm, entirely white or white with a small reddish-purple spot at the apex of each lobe; posterior portion of midlobe ovate, 5.5–8.6 × 4.9–8.2 mm, entirely white or white with randomly arranged small reddish-purple spots, margin slightly irregularly erose-denticulate. Column slightly curved, 8.5–15 × 2.7–4 mm at the widest part (a little below the top) and 1.7–3.2 mm wide at the base, semi-cylindrical with column wings at the lateral part of the apex and 1 appendage at the central part of the apex; rostellum well-developed; stigma located just below the rostellum, 0.9–3.5 × 0.8–3.2 mm. Anther hemispheric, 0.9–1.4 mm in diameter; pollinia 4, in 2 pairs, obovoid, 0.8–1.1 × 0.6–0.9 mm; viscidium rhomboid, 0.6–0.9 mm long. Capsule obovoid, 1.9–2.5 cm long.

Additional specimens examined:— RUSSIA. Kuril Islands— Shikotan Island: Shikotan-mura, Chiboi , 10 August 1931, Ono s.n. ( SAPS) ; loc. cit., 3 August 1934, Tatewaki 20876 ( SAPS) ; loc. cit., 8 July 1934, Ono s.n. ( TNS) ; loc. cit., 10 August 1931, Ono 32 ( TI) ; Shikotan-mura, 1937, unknown collector s.n. ( TNS) . JAPAN. Hokkaido District — Hokkaido Pref.: Nemuro-shi, Ochiishi-higashi , 7 July 2021, Shutoh & Yano Da 10 ( KYO) ; loc. cit., 7 July 2021, Shutoh & Yano 4851 ( SAPS) ; loc. cit., 18 July 2023, Shutoh Da 12 ( KYO) ; Nemuro-shi, Ochiishi , 2 July 1927, Kondo s.n. ( TI) ; Ashoro-gun, Ashoro-cho, Moashoro , Mt. Meakan , 19 July 1981, Takita 510 ( KYO) ; Kitami-shi, Oketo-cho , August 1930, Okamoto s.n. ( SAPS) ; Kato-gun, Kamishihoro-cho, Kamiotofuke, date unknown, Amikawa & Konno s.n. ( SAPS) ; Kawakami-gun, Kawakami-cho, Mts. Taisetsu , 26 July 1937, Hara s.n. ( TI) ; Hidaka-gun, Shinhidaka-cho, Shizunaitakami , Mt. Petegari , 16 July 1976, Samejima & Sato 76, 0158 ( SAPS) ; Kamikawa-gun, Higashikawa-cho, Mt. Asahidake , Mts. Taisetsu , 29 July 1917, Koizumi 77970 ( TNS) ; Kamikawa-gun, Higashikawa-cho, Mts. Taisetsu , 18 July 1941, Okuyama s.n. ( TNS) ; Saru-gun, Hidaka-cho, Nukabira , 11 July 1952, Nishimura s.n. ( SAPS) ; Sorachi-gun, Minamifurano-cho, Kanayama , Mt. Yubari , 12-14 July 1934, Ohwi 4986 ( KYO) ; Nakagawagun, Otoineppu-mura, Monomanai , 12 July 1930, Terho s.n. ( SAPS) ; along the Ishikari River, 30 July 1952, Tatewaki & Takahashi 43251 ( SAPS). Tohoku District — Iwate Pref.: Miyako-shi , Mt. Hayachine , 9 July 1905, Miura s.n. ( SAPS) ; loc. cit., 15 July 1968, Enomoto 4666 ( SAPS) ; loc. cit., 15 July 1968, Enomoto 4667 ( SAPS) ; loc. cit., 15 July 1968, Enomoto 4668 ( SAPS) ; Tono-shi, Tsukimoushi-cho, Kamitsukimoushi , Mt. Hayachine , 17 July 1936, Muroi s.n. ( KYO) ; Miyako-shi, Mt. Hayachine , 9 July 1905, Miura s.n. ( SAPS) ; loc. cit., 27 June 1913, Tamaki s.n. ( TNS) ; loc. cit., 7 July 1933, Toba 90 ( TI) ; loc. cit., 27 June 1913, Hayakawa s.n. ( TI) ; Hanamaki-shi, Mt. Keito, Mts. Hayachine , 16 July 1926, Okada s.n. ( TNS) ; Nambu, 1865–1866, Tschonoski (=Sukawa) s.n. ( LE). Akita Pref.: Oga-shi , Funagawaminatohonzanmonzen , Mt. Hon , 18 June 1933, Muramatu s.n. ( TI). Fukushima Pref.: Minamiaizu-gun, Hinoemata-mura, Numayama-toge, date unknown, Hayata 16491 ( SAPS). Kanto District— Gunma Pref.: Agatsuma-gun, Tsumagoi-mura, Hoshimata, Manza-toge, 7-8 July 1929, Koizumi 55271 ( TNS) ; Agatsuma-gun, Nakanojo-cho, Iriyama , 22 June 2023, Matsui, Ichikura & Ichikura ( KYO). Saitama Pref.: Chichibu-shi, Nakatsugawa, Jumonji-toge, 17 June 1950, Shimizu s.n. ( TNS). Chubu District— Niigata Pref.: Minamiuonuma-gun, Yuzawa-cho, Mikuni, Mt. Naeba , 15 July 1927, Ohwi s.n. ( KYO). Toyama Pref.: Toyama-shi, Arimine, en route from Magawa River to Tarobeidaira, 22 July 1936, Hisauchi 1608 ( TNS). Yamanashi Pref.: Kitatsuru-gun, Kosuge-mura, en route from Daibosatsu-toge to Mt. Koganesawayama , 16 July 1962, Murata 27030 ( KYO) ; Fujiyoshida-shi, Kamiyoshida, Mt. Fuji , 7 July 1977, Inoue & Sugiyama s.n. ( TI) ; Kofu-shi, Kurobera-cho, Mt. Kinpu , 2 July 1948, Shimizu s.n. ( TNS). Nagano Pref.: Minamisaku-gun , Kawakami-mura , Jumonji-toge , 10 July 1960, Soma s.n. ( TNS) ; Shimotakai-gun, Yamanouchi-machi, Hirao , Mt. Akaishi , 14 July 1933, Katumata 18657 ( TI) ; loc. cit., 10 July 1971, Tateishi s.n. ( TI) ; Chino-shi, Mt. Yatsugatake , 13 July 1930, Asuyama s.n. ( TNS) ; Chino-shi, Karasawa-toge, Mt. Yatsugatake , 9 August 1938, Watari s.n. ( TI) ; loc. cit., 9 July 1938, Hara s.n. ( TI) ; loc. cit., 9 July 1938, Hara s.n. ( TI) ; Ina-shi, Hasekurogochi, Mt. Senjogatake , 31 July 1949, Furusawa s.n. ( TI) ; Shimoina-gun, Oshika-mura, Kashio , Mt. Hontani , 25 July 1949, Furusawa s.n. ( TI) ; Shimoina-gun, Oshika-mura, Sanpukutoge , 30 July 1927, Saito s.n. ( TI) ; Kiso-gun, Agematsumachi, Mt. Komagatake , 13 July 1948, Satomi s.n. ( TNS) ; loc. cit., 20 July 1924, Muramatu s.n. ( TI) ; Azumino-shi, Hotakaariake, Mt. Ariake , 21 July 1921, Koizumi 1885 ( TNS). Shizuoka Pref.: Fujinomiya-shi , Awakura , Mt. Fuji , 22 September 2021, Sato Da 2 ( KYO) ; loc. cit., 28 June 2022, Sato Da 9-1 ( KYO) ; loc. cit., 28 June 2022, Sato Da 9-2 ( KYO) ; loc. cit., 28 June 2022, Sato Da 9-4 ( KYO) ; loc. cit., 28 June 2022, Sato Da 9-5 ( KYO) ; Shizuoka-shi, Aoi-ku, Tashiro , Mt. Hijiridake , July 1921, Sawada s.n. ( TI) .

Vernacular name:— Takane-ichi-yo-ran, nov. (in Japanese). The term “ichi-yo-ran” originates from the Japanese name for D. ringens , indicating an orchid species with a single leaf per individual. Dactylostalix uniflora prefers cooler environments compared to D. ringens , frequently found at higher elevations. Hence, the prefix “Takane”, which translates to high peaks or mountaintops, has been appended to the vernacular name of D. ringens .

Taxonomic notes:— Pergamena uniflora was described based on specimens from Mt. Hayachine, Iwate Prefecture, collected on 14 June 1894 by Urbanus Jean Faurie ( Finet 1900). Although Finet (1900) described the labellum as free and unlobed, both line drawings in Finet (1900) and the original materials of P. uniflora show small but noticeable lateral lobes ( Figs. 3–4 ). Although it differs from D. ringens in several morphological aspects, including smaller lateral lobes and more distinct keels on the adaxial surface of the lip, these differences do not justify separating it into a separate genus. Thus, we propose the combination D. uniflora (Finet) Suetsugu , as it is considered a distinct species within the genus Dactylostalix . We designate P00420868 as the lectotype and P00420869 & K000943526 as isolectotypes of P. uniflora (= D. uniflora ), as P00420868 is most illustrative of the lateral lobe shape, a key diagnostic characteristic, and the line drawings in Finet (1900) were based on this specimen. Notably, no D. ringens specimens were found in Mt. Hayachine, the type locality of D. uniflora , according to our herbarium survey.

Morphological notes:— Dactylostalix uniflora is morphologically similar to D. ringens , but can be easily distinguished by its smaller lateral lobe (obliquely narrowly triangular to ovate, 3.0–6.8 × 0.4–2.0 mm, entirely white or white with a small reddish-purple spot, versus semiorbicular, 5.0–9.3 × 2.8–4.0 mm, white with a large reddish-purple spot in D. ringens ). Notably, D. uniflora exhibits variations in the size and shape of the lateral lobe, ranging from nearly absent to somewhat developed. However, even those relatively developed lobes are smaller than the semiorbicular lobes found in D. ringens . Additionally, D. uniflora is distinguishable from D. ringens by its shorter scape, smaller flower, less spotted tepals, drooping sepals and lateral petals, labellum with smaller lateral lobes, more distinct keels on the adaxial surface of the lip, and a slender column with a smaller stigma and weakly developed clinandrium.

Preliminary conservation status: —Our field and herbarium surveys indicate that D.uniflora is much less common than its closely related species D. ringens . Each population often contains fewer than 20 D. uniflora individuals, and even in the population (Mt. Fuji) that likely supports the largest number of individuals, the population size is estimated to be approximately 50. Therefore, we consider the conservation status of D. uniflora to be “Vulnerable” according to the IUCN criteria (IUCN 2019) under the D1 criteria, as it is estimated to have fewer than 1000 mature individuals.

Figures

FIGURE 1. Morphological comparison of Dactylostalix ringens (A–C) and D. uniflora (D–F). (A) Flowering plant in Ena-shi, Gifu Pref. (B–C) Flower in Mt. Fuji, Fujinomiya-shi, Shizuoka Pref. (D) Flowering plant in the Akaishi Mountains, Yamanashi Pref. (E–F) Flower in Mt. Fuji, Fujinomiya-shi, Shizuoka Pref. Scale bars: 30 mm (A, D) and 10 mm (B–C & E–F).

FIGURE 3. Lectotype of Pergamena uniflora designated in the present study (P00420868). (A) Habit. (B) Flower, lateral view. (C) Labellum. Black arrows indicate small ovate side lobes. Scale bars: 50 mm (A), 10 mm (B), and 5 mm (C).

FIGURE 4. Line drawing of Pergamena uniflora based on P00420868. (A) Habit. (B) Dorsal sepal. (C) Lateral sepal. (D) Lateral petal. (E) Column, labellum, and ovary. (F) Labellum. (G) Apical part of the column, ventral view. (H) Apical part of the column, oblique ventral view. (I) Anther cap, lateral view. (J) Anther cap, ventral view. (K) Pollinarium. Scale bars: 20 mm (A), 10 mm (B–E), 5 mm (F–H), and 2.5 mm (I–K). Reproduced from Finet (1900).

FIGURE 8. Original materials of Calypso japonica (LE01012252 & LE01012253). (A) Habit (Upper: LE01012252 & Lower: LE01012253). (B) Flower, front view (LE01012252). (C) Flower, lateral view (LE01012252). Black arrows indicate small, narrowly triangular side lobes. Scale bars: 50 mm (A) and 10 mm (B–C).

FIGURE 12. Dactylostalix uniflora (Masayuki Sato Da2, KYO). (A) Habit. (B) Flower, lateral view. (C) Column, labellum, and ovary. (D) Dorsal sepal. (E) Lateral petal. (F) Lateral sepal. (G) Labellum. (H) Flatten labellum. (I) Column. (J) Pollinarium on the apical part of the column. (K) Anther cap and pollinarium. Scale bars: 30 mm (A) and 5 mm (B–K).