Microsaccus Explained

Microsaccus is a genus of flowering plants from the orchid family, Orchidaceae. It is native to Southeast Asia.^[1]

Description

Vegetative characteristics

These miniature epiphytes produce laterally flattened, distichously arranged leaves on thin stems.^[2]

Generative characteristics

The usually two-flowered inflorescences are short.^[3] The spurred, minuscule flowers have a simple labellum. The flowers have four pollinia.^[4] Within the fruits there are pale brown to whitish trichomes with an oblong-elliptic basal zone. They have perforations in the basal region.^[5]

Etymology

The generic name Microsaccus is composed of the Greek words μικρός (mikrós) meaning small and saccus meaning sack, which refers to the labellum.^[6]

Ecology

Microsaccus truncatus is known to grow epiphytically in montane forest at 1200 m above sea level. Microsaccus griffithii occurs in forests at elevations of 500–2770 m above sea level.

Physiology

Microsaccus uses CAM photosynthesis.^[7]

Taxonomy

Species

The genus contains 13 accepted species:

1. Microsaccus affinis J.J.Sm. - Java
2. Microsaccus albovirescens J.J.Sm. - Sumatra
3. Microsaccus ampullaceus J.J.Sm. - Sumatra, Borneo, Malaysia
4. Microsaccus borneensis J.J.Sm. - Borneo
5. Microsaccus canaliculatus J.J.Sm. - Sumatra
6. Microsaccus dempoensis J.J.Sm. - Sumatra
7. Microsaccus griffithii (C.S.P.Parish & Rchb.f.) Seidenf. - Cambodia, Myanmar, Thailand, Vietnam, Borneo, Malaysia, Java, Sumatra, Philippines
8. Microsaccus javensis Blume - Malaysia, Java
9. Microsaccus mihoae P.O'Byrne & Gokusing - Borneo
10. Microsaccus ramosus J.J.Sm. - Java
11. Microsaccus sumatranus J.J.Sm. - Malaysia, Sumatra
12. Microsaccus truncatus Carr - Malaysia
13. Microsaccus wenzelii Ames - Philippines

Phylogeny

It is closely related to the genus Jejewoodia . One species, namely Jejewoodia longicalcarata (Ames & C.Schweinf.) J.J.Wood used to be Microsaccus longicalcaratus Ames & C.Schweinf.^[8] It has been suggested to reunite these two genera, due to their similar appearance. Another closely related genus is Adenocos, which does not have a spur, unlike the former two genera.^[9]

Horticulture

Microsaccus can be cultivated under moist conditions with a lot of air movement, and intermediate temperatures. The plants should be placed in a semi-shaded position. It is rarely cultivated.

See also

• List of Orchidaceae genera

Notes and References

1. 29983-1

   . Microsaccus Blume . 9 January 2022.
2. Teoh, E.S. (2021). Microsaccus Bl. In: Orchid Species from Himalaya and Southeast Asia Vol. 2 (G - P). Springer, Cham. https://doi.org/10.1007/978-3-030-80428-2_18
3. Seidenfaden, G., Wood, J., & Holttum, R. (1992). "The Orchids of Peninsular Malaysia and Singapore." Olsen & Olsen.
4. Zou, L. H., Huang, J. X., Zhang, G. Q., Liu, Z. J., & Zhuang, X. Y. (2015). "A molecular phylogeny of Aeridinae (Orchidaceae: Epidendroideae) inferred from multiple nuclear and chloroplast regions." Molecular phylogenetics and evolution, 85, 247–254.
5. Gamarra, R., & Ortúñez, E. (2021). "Endocarpic trichomes in Vandeae (Orchidaceae)." Flora, 280, 151844.
6. Puccio, P. (n.d.). Microsaccus truncatus. Monaco Nature Encyclopedia. Retrieved January 9, 2023, from https://www.monaconatureencyclopedia.com/microsaccus-truncatus/
7. Microsaccus griffithii. (n.d.). Hortus Orchis. Retrieved January 9, 2023, from https://www.hortusorchis.org/en/botanical-orchids/118-m/1483-microsaccus-brevifolius.html

8. 77109445-1

   . Jejewoodia longicalcarata (Ames & C.Schweinf.) J.J.Wood . 9 January 2022.
9. Pridgeon, A., Cribb, P., Chase, M., & Rasmussen, F. (2014). "Genera Orchidacearum Volume 6: Epidendroideae (Part 3)." pp. 118, 204, 212. OUP Oxford.