2. 中国科学院东南亚生物多样性研究中心, 叶津, 比都, 缅甸;
3. 白雪山国家公园管理局, 葡萄, 克钦邦, 缅甸
2. Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar;
3. Hkakarborazi Natural Park, Putao, Kachin State, Myanmar
The monocot family Petrosaviaceae consists of approximate two genera and ca. four species, and is widespread in tropical and subtropical regions in Asia[1-3]. Petrosaviaceae is characterized by achlorophyllous plants, reduced leaves scalelike, spiral along the stem, flowers white and actinomorphic, stamens 6, 3 carpels connate for 1/4-1/2 their length, fruit a capsule, follicle-like[1-4].
During our botanical survey in northern Myanmar, Petrosavia sakura, a species representing a new familial and order record of flora of Myanmar (see references [5, 6]), was discovered and described below.
Petrosavia sakuraii (Makino) J. J. Sm. ex Steenis, Trop. Nat. 23: 52. 1934.
Miyoshia sakuraii Makino, Bot. Mag. (Tokyo) 17: 145. 1903.
Type: Japan. Mino, foot of Mt. Ena, shady forests, 27 Jul. 1903, H. Sakurai s.n (TI).
Mycoheterotrophic plants, herbs, whitish pale yellow, 7-15 cm tall, glabrous. Rhizome ca. 2 mm thick, enclosed by dense bracts. Stems slender, erect, 1 or 2 arising from rhizome. Leaves reduced and scale-like, rather lax, usually 1-2 cm apart, spiral along the stem, narrowly to broadly ovate, acuminate, 2-5 mm long, membranous, 1-veined. Inflorescence a raceme, more or less corymbose, 2-10 cm long, up to more than 10-flowered; bracts lanceolate to ovate, 2-5 mm, slightly shorter than pedicel. Pedicel 3-7 mm long. Flowers very small. Tepals (perianth) adnate for ca. 1/3 its length to ovary, persistent; outer segments triangular, inner segments ovate-deltoid; segments 1-veined, outer ones 0.8 mm×ca. 1 mm, inner ones 2 mm×ca. 2 mm. Stamens 6, ca. 1 mm long; anthers ovate. Ovary broadly ovoid, 3-partite. Capsule ca. 3 mm×3 mm. Fl. June-Aug., fr. Oct. 2n=60.
Habitat: Under humid montane evergreen broad- leaved forest, 2 200 m.
Distribution: China, Japan, and Myanmar (new record).
Flowering Period: June to Aug.
Specimens examined. Myanmar. Kachin State, Putao County, June 17, 2016, Ziyardam, Jin X. H., Wang R. J. & Chen Y. S. PT-2277 (PE).
Petrosavia sakuraii is a rare but widespread species in montane regions of subtropical and tropical Asia[1, 3]. It is readily distinguished from its Asian relatives by scalelike leaves on stem usually 1-2 cm apart; inflorescence a raceme, more or less corymbose (Fig. 1), fertile bracts slightly shorter than pedicel, and tepals adnate for ca. 1/3 its length to ovary[1, 3, 7].
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