TRIURIDACEAE [Draft]

霉草科  mei cao ke

Guo Youhao (郭友好)^[1]; Martin Cheek^[2]

Saprophytic herbs (achlorophyllous mycotrophs) reddish, purple, or yellow. Stems erect, simple or nearly so. Leaves alternate, reduced, scale-like, not green. Plants monoecious or dioecious; flowers small, unisexual, rarely bisexual or polygamous, actinomorphic, in racemes or subcorymbs, with decurved bracteate pedicels. Perianth segments 3–10, in 1 series, valvate, usually united at base, sometimes appendaged at apex, reflexed after anthesis. Stamens 2–6, inserted at base of receptacle or perianth; anthers 2- or 4-thecous, extrorse, mostly opening by transverse slit; connective often reduced into long subulate appendages. Carpels 6 to many, free; style terminal to nearly basal; ovule solitary, basal. Fruiting carpels crowded, opening by a slit. Seed with a fleshy white oily undifferentiated nucleus.

Eleven genera and ca. 50 species: tropics and subtropics; one genus and five species in China.

1. SCIAPHILA Blume, Bijdr. 514. 1825–1826 ('1825').

喜荫草属  xi yin cao shu

Roots with hairs. Stems short, slender. Inflorescences racemose; flowers unisexual or bisexual, pedicellate. Perianth segments 3–8(–10). Stamens 2, 3, or 6; filaments absent or very short; anthers 3- or 4-thecous; connectives not produced into appendages. Carpels numerous; style lateral or basal. Follicles opening by a longitudinally slit.

About 30 species: tropics and subtropics; five species in China.

1a.     Plants with male and bisexual flowers.

2a.    Male flowers with 6 stamens; bisexual flowers with 3–6, but generally 6 stamens  1. S. tenella

2b.    Male and bisexual flowers with 3 stamens ...................................................  2. S. maculata

1b.     Plants without bisexual flowers, monoecious.

3a.    Style club-shaped, stems 0.6–1 mm in diam. ..........................................  3. S. secundiflora

3b.    Style awl-shaped, stems 0.3–0.5 mm in diam.

4a.     Stems mostly not branched, pedicels 7–9 mm ........................................  4. S. arfakiana

4b.     Stems branched; pedicels 2–3.5 mm .........................................................  5. S. ramosa

 

1. Sciaphila tenella Blume, Bijdr. 2: 515. 1825.

喜荫草  xi yin cao

Stems 7–18 cm tall. Scale-like leaves broadly ovate, ca. 2 mm, amplexicaul at base. Inflorescences 5–14 cm. Flowers bisexual and male. Pedicel 4–6 mm, decurved after anthesis; bracts lanceolate, ca. 2 mm. Perianth segments of bisexual flowers 6, apex acute to acuminate and crinite; stamens 6; carpels ca. 20; styles short, lateral. Perianth segments of male flowers similar with bisexual ones; stamens 6; filaments short, united at base. Follicles 1.5–2 mm in diam. Seeds elliptical, 3-ribbed. Fl. summer.

Forests. Hainan (Aixian) [Indonesia, Japan, Malaysia, New Guinea, Philippines, Sri Lanka; Pacific islands (Solomon Isl.)].

2. Sciaphila maculata Miers, Proc. Linn. Soc. London 2: 72. 1850.

斑点霉草  BAN DIAN MEI CAO

Stems ca. 10 cm tall. Scale-like leaves oblong, ca. 1.2 mm. Inflorescences ca. 7 cm, 30-flowered. Flowers bisexual and male. Pedicels 4–6 mm, decurved after anthesis; bracts lanceolate, 1–1.2 mm. Perianth segments 6, 3 broad segments alternating with 3 narrower ones, ca. 0.6 mm; stamens 3, anthers 3-lobed, filaments short; carpels ca. 20–30; styles basal, club-shaped, apex papillate, exceeding ovary. Follicles ca. 2 mm in diam. Seeds ellipsoid, 3-grooved on adaxial side.

Forests. Taiwan (Taitung) [Malaysia (Borneo), New Guinea, Philippines].

Ohashi & Murata (2008. J. Jap. Bot. 83: 20–35) treat this taxon as synonymous with Sciaphila tenella; however, one of us (Guo) notes that the stamen number differs.

3. Sciaphila secundiflora Bentham, Hooker's J. Bot. Kew Gard. Misc. 7: 10. 1855.

大柱霉草  da zhu mei cao

Sciaphila megastyla Fukuyama & T. Suzuki.

Stems usually simple, 4–12 cm tall including inflorescences. Scale-like leaves ovate-lanceolate, 2–4 mm, apex mucronate or retuse. Inflorescences short, 3–9-flowered. Plants monoecious; pedicels slightly curved upward; bracts 1–3 mm. Perianth segments 6, subulate, 2–3 mm. Stamens 3 or 2, sessile. Carpels claviform and attenuate toward base when mature; styles nearly basal, claviform.

About 300 m. Hong Kong, Taiwan (Ilan, Lanyu) [Indonesia, Japan, Malaysia, New Guinea, Sri Lanka; Pacific islands (Solomon Isl.)].

4. Sciaphila arfakiana Beccari, Malesia 3: 337. 1890.

兰屿霉草  LAN YU MEI CAO

Stems 6–12 cm tall. Scale-like leaves oblong, ca. 1 mm. Inflorescences 1–5 cm, 5–30-flowered. Flowers unisexual. Pedicels (4–)7–9 mm, spreading; bracts lanceolate, ca. 1 mm. Perianth segments 6, segments oblong, ca. 1.3 mm, apex with stipitate globose apex; stamens (2 or)3, anther 4-celled. Female flower with segments ca. 0.5mm, apex without appendage; carpels ca. 20–30, styles subapical, awl-shaped, apex papillate, exceeding ovary. Follicles ca. 2 mm in diam. Seeds ca. 0.7 mm.

Forests. Taiwan (Lanyu Isl.) [Malesia, Micronesia, W Polynesia, Solomon Isl.]

According to Jin Murata (pers. comm.), this taxon may be the same as Sciaphila nana. One of us (Guo) notes that it is better to keep these separate at this time, awaiting further research.

5. Sciaphila ramosa Fukuyama & T. Suzuki, J. Jap. Bot. 12: 414. 1936.

多枝霉草  duo zhi mei cao

Stems branched, ca. 12 cm tall including inflorescences. Scale-like leaves lanceolate, apex mucronate. Inflorescences short, 3–7-flowered. Plants monoecious; pedicels erect, ca. 4 mm, slender; bracts 1.5–2 mm. Perianth segments (4–)6, ovate or ovate-lanceolate, ca. 0.8 mm. Stamens 2 or 3, subsessile. Carpels obovoid and slightly curved when mature; styles nearly apical, filiform.

About 300 m. Taiwan (Lanyu) [Japan (Bonin Isls)].