Microtis globula

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Globular mignonette orchid
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Genus: Microtis
Species:
M. globula
Binomial name
Microtis globula

Microtis globula, commonly known as the globular mignonette orchid[2] or globular onion orchid[3] is a species of orchid endemic to the south-west coastal region of Western Australia. It has a single hollow, onion-like leaf and up to thirty five small greenish-yellow, almost globe-shaped flowers. It often grows in large colonies but only flowers after hot fires the previous summer.

Description[edit]

Microtis globula is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, smooth, tubular leaf 100–250 mm (4–10 in) long and 3–4 mm (0.1–0.2 in) wide. Between eight and thirty five greenish-yellow flowers are arranged along a flowering stem 200–350 mm (8–10 in) tall. The flowers are almost globe-shaped, about 2.5 mm (0.1 in) long and wide. The dorsal sepal is egg-shaped to almost round, about 2 mm (0.08 in) long and wide and hood-like. The lateral sepals are triangular, about 2 mm (0.08 in) long, 1 mm (0.04 in) wide and curved with their upper edge partly overlapping the dorsal sepal. The petals are egg-shaped, about 1.5 mm (0.06 in) long, 1 mm (0.04 in) wide and are surrounded by the sepals. The labellum is 1.5–2 mm (0.06–0.08 in) long, about 1 mm (0.04 in) wide and lacks an obvious callus. Flowering occurs from December to January but only after a hot or late fire the previous summer.[2][3][4]

Taxonomy and naming[edit]

Microtis globula was first formally described in 1984 by Robert John Bates from a specimen collected near Walpole and the description was published in Journal of the Adelaide Botanic Gardens.[5] The specific epithet (globula) is from the Latin word "globulus" meaning "a little ball" or "globule", referring to the shape of the flowers.[2][6]

Distribution and habitat[edit]

The globular mignonette orchid grows in peaty, winter-wet areas between Albany and Northcliffe in the Jarrah Forest and Warren biogeographic regions.[2][3][7]

Conservation[edit]

Microtis globula is classified as "Priority Four" by the Government of Western Australia Department of Parks and Wildlife,[7] meaning that is rare or near threatened.[8] It is also classified as "vulnerable" under the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act. The main threat to the species is inappropriate fire regimes.[9]

References[edit]

  1. ^ "Microtis globula". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. ^ a b c d Brown, Andrew; Dundas, Pat; Dixon, Kingsley; Hopper, Stephen (2008). Orchids of Western Australia. Crawley, Western Australia: University of Western Australia Press. p. 287. ISBN 9780980296457.
  3. ^ a b c Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. pp. 224–225. ISBN 1877069124.
  4. ^ Bates, Robert J. (1984). "The genus Microtis R.Br. (Orchidaceae): a taxonomic revision with notes on biology" (PDF). Journal of the Adelaide Botanic Gardens. 13: 60–62. Retrieved 25 February 2018.
  5. ^ "Microtis globula". APNI. Retrieved 25 February 2018.
  6. ^ Francis Aubie Sharr (2019). Western Australian Plant Names and their Meanings. Kardinya, Western Australia: Four Gables Press. p. 208. ISBN 9780958034180.
  7. ^ a b "Microtis globula". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  8. ^ "Conservation codes for Western Australian Flora and Fauna" (PDF). Government of Western Australia Department of Parks and Wildlife. Retrieved 3 April 2020.
  9. ^ "Approved Conservation Advice for Microtis globula (South-Coast Mignonette Orchid)" (PDF). Australian Government Department of the Environment. Retrieved 25 February 2018.

External links[edit]