The monocot family Triuridaceae consists of approximate 11 genera and ca. 50 species and is widespread in tropical and subtropical region around the world^[1-2]. Triuridaceae is characterized by achlorophyllous plants, leaves alternate, reduced and scalelike, small flowers actinomorphic, sometimes appendaged at apex, stamens 2-6 inserted at base of receptacle or perianth, carpels 6 to many, ovule solitary, fruiting carpels crowded, opening by a slit^{[1, 2]}.

During our botanic survey in northern Myanmar, Sciaphila nana, a species representing a new familial record of flora of Myanmar^[3], was discovered and here described below.

Sciaphila nana Blume, Mus. Bot. 1: 322. 1851, Meerendonk in Fl. Males. Ⅰ. 10: 117. 1984. Fig. 1.

(Fig. 1)

Fig. 1 Plants of Sciaphila nana Blume. A: Habit of Sciaphila nana in Putao, Kachin, Myanmar; B: Close up of female flowers (live plants); C: Close up of male flower (dry specimens)

Terrestrial herbs, mycotrophic, plants violet. Stems delicate, erect, 5-10 cm long, ca. 0.5 in diam., glabrous. Leaves scale-like, entire, concave and appressed to stem, ovate-lanceolate, acute, 2-2.2 mm long, 1 mm wide. Inflorescences raceme, ca. 2 cm long; bracts lanceolate, ca. 1.5 mm long, pedicel about 1.5-2 mm long. Flowers unisexual, approximately 7-to 10-flowered, male flowers above, female ones below, sometime mixed. Male flowers about 2 mm in diam.; 6 tepals, outer 3 larger than inner 3; the larger tepals oblong, 1.5 mm long, 0.5 mm wide; inner tepals 0.8-1 mm long, with ellipsoid knob at apex; stamens 3, filaments 0.2 mm long, anthers 4-celled. Female flowers ca. 2 mm in diam.; pedicel 2.5-3 mm long; tepals 3, oblong, ca. 1 mm long, ca. 0.6 mm wide, oblong, acute; carpels 30-40, ovate; style awl-shaped, 0.5 mm long, inserted laterally near the top, apex acute.

Distribution. Indonesia, Malaysia, Myanmar (new record), Philippines, Thailand, Vietnam.

Ecology. Growing on soil, under humid seasonal tropical rainforest, ca. 500 m in altitude.

Flowering Period: April to May.

Specimens examined. Myanmar. Kachin State, Putao County, Maojiaowan Village, Jin X. H., Zhu X. Y. & Han M. Q. PT-6990, May 21, 2017 (PE).

Sciaphila nana is rare but widespread species in Southeast Asia^[4-6]. It is readily distinguished from its Asian relatives by monoecious plants (plants with bisexual flowers in S. maculata and S. tenella), tepals of female flowers entire (long hairs in S. arcuata), anther 4-celled (1-celled in S. stellata, 2-celled in most other species, such as S. jingfenglingensis), inner tepals of male flowers with stipulate knob (all tepals of male flowers with stipulate knob in S. arfakiana), style awl-shaped (club-shaped in S. secudiflora)^[4-10].

Sciaphila nana is closely related to S. khasiana Benth. & Hook. f. from Bangladesh by sharing small status plants, racemose inflorescence and four-celled anthers, but differs from the latter by its flowers with 6 tepals (4-5 tepals in S. khasiana), monoecious plants (dioecious in S. khasiana), and male flowers usually without subulate pistillodes (3 in male flowers of S. khasiana)^[11].