CORSIACEAE [Draft]

 

Zhang Dianxiang (张奠湘)[1], Hu Qiming (胡启明 Hu Chi-ming)1; Richard M. K. Saunders[2]

 

Herbs, perennial, achlorophyllous, holomycotrophic, rhizomatous or tuberous. Stem unbranched. Leaves alternate, amplexicaul, small. Flowers solitary, terminal, bisexual or unisexual, epigynous. Perianth of 6 tepals in two whorls, zygomorphic; posterior tepal large, broad, sometimes with basal callus; other tepals linear-filiform. Stamens 6; filaments short; anthers dorsifixed, dehiscence extrorse; pollen (not known from Corsiopsis) 1‑aperturate. Gynoecium syncarpous, 3-carpellate; ovary unilocular with 3 parietal placentae; ovules numerous, anatropous, bitegmic, tenuinucellate. Style absent or short; stigmas 3. Fruit (not known from Corsiopsis) capsular, with 3 valves. Seeds (not known from Corsiopsis) numerous, very small, winged; embryo rudimentary at time of release.

 

                Three genera and 29 species; S America, Australia, New Guinea, Solomon Islands; one genus and one species (endemic) in China.

 

1. CORSIOPSIS D. X. Zhang, R. M. K. Saunders & C. M. Hu, Syst. Bot. 24: 313. 1999.

 

bai yu zan

 

Flowers unisexual. Outer whorl posterior tepal erect, a distinct labellum, without a basal callus; lateral tepals 2, pendulous; inner whorl tepals 3. Male flowers: stamens 6, in 2 whorls. Female flowers: stigmas sessile, connate.

 

                One species: endemic to China.

 

1. Corsiopsis chinensis D. X. Zhang, R. M. K. Saunders & C. M. Hu, Syst. Bot. 24: 313. 1999.

 

bai yu zan

 

                Plant white. Rhizome ellipsoid-obovoid, 12--15 X ca. 5 mm. Stem solitary, 5--6 cm. Leaves ovate-triangular, 4--7 mm, membranous, apex acute; many-veined. Bracts subtending flowers ovate-triangular, 4--7 mm. Perianth white; posterior tepal elliptic, bladder-like, 12--14 X ca. 10 mm; inner whorl tepals linear, 4.5--6 cm. Staminal connective with an obtuse apical extension. Ovary elongated, ca. 5 mm. Fruit and seeds not seen. Fl. June.

 

                * Dense forests, on humus-rich soil. Guangdong (Fengkai).

 



[1] South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650.

[2] Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong.