Orchidantha

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Orchidantha
Orchidantha maxillarioides, illustration

Orchidantha maxillarioides , illustration

Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Commelinids
Order : Gingery (Zingiberales)
Family : Lowiaceae
Genre : Orchidantha
Scientific name of the  family
Lowiaceae
Ridl.
Scientific name of the  genus
Orchidantha
NEBr.

Orchidantha is the only genus of the family of Lowiaceae that the monocotyledonous plant belongs (monocots). The generic name Orchidantha means "orchid flower" because a bloom is convertedinto a labellum , like the flowers of the orchids . The genus Orchidantha includes about (two) 12 to 23 species. Nothing is known about the use of the species; some botanical gardens display one or a few species.

Description and ecology

Orchidantha fimbriata , flower
Habitus, stalked leaves and basal flowers of Orchidantha maxillarioides

Appearance and leaves

Orchidantha species are perennial herbaceous plants with short stems and creeping rhizomes . The alternate and two-line arranged, simple leaves are divided into long petioles and leaf blades (not typical for monocot but often in ginger-like (Zingiberales)). The leaf blades have a clearly raised midrib and a few pairs of parallel main nerves that are connected to fine side nerves.

Inflorescences and flowers

The axillary or direct the rhizomes springing zymösen inflorescences (inflorescences) are wenigblütig or only einblütig, with bracts (bracts). In some species, most of the inflorescence is underground. The flowers often smell bad. The hermaphrodite flowers are zygomorphic and threefold. The bracts are designed differently. The three sepals are fused into a long, thin tube. Of the three very unequal petals , the middle one is transformed into a large labellum, depending on the type, facing upwards or downwards, and the two lateral ones are only small. There are five fertile stamens with short stamens per flower . The three pistils have become an under constant (syncarp) ovary grown. The stylus ends in three-lobed scars , which, depending on the species, are typically toothed or fringed; this is a feature that clearly distinguishes them from related families. The flowering period of a single flower is only one day.

The pollination is effected by insects ( Entomophilie ), mainly by Diptera . The species Orchidantha inouei from Borneo, imitates the smell of dung to attract small beetles of the genus Onthophagus as pollinators .

Fruits and seeds

Three-chamber, loculicidal capsule fruits are formed that contain many seeds. The spherical, hairy seeds have a three-lobed aril .

Systematics and distribution

Botanical history

The generic name Orchidantha was published by Nicholas Edward Brown in Gardens Chronicle II, 26, 519 in 1886 . Type species is Orchidantha borneensis N.E.Br. More recent adaptations of the genus Orchidantha also assign the species of the former genera Lowia Scort. , Protamomum Ridl. and Wolfia Post & Kuntze here. The genus name Lowia was also published by Benedetto Scortechini in Nuovo Giornale Botanico Italiano , XVIII, 308 in 1886 , but not until 2 days later than the publication by Nicholas Edward Brown, so Orchidantha was given priority. The generic name Lowia honors Sir Hugh Low (1824-1905), an orchid specialist. Previously, these species were included as the subfamily Lowioideae in the Musaceae family . The family name Lowiaceae was found in 1924 by Henry Nicholas Ridley in On the flora of the eastern coast of the Malay Peninsula. , 4, p. 291. A synonym for Lowiaceae Ridl. is Orchidanthaceae Dostál .

Occurrence, relationship and evolution

Their distribution is purely South and Southeast Asian: from southern China via Cambodia , Laos , Vietnam , Malaysia to Indonesia ( Borneo ). They are mostly found in moist humus soils in evergreen rainforests, where they cover large areas of the forest floor.

Closest related to the Lowiaceae is the Strelitziaceae , which is also small ; they are both native to Southeast Asia, and their two lineages probably only separated 80 million years ago. Their common lineage separated from the Neotropical Heliconiaceae about 109 million years ago. The common ancestors of these three lines thus had a Gondwana distribution.

Species their distribution

There are (two to twelve to) around 17 Orchidantha species or 23 species since 2010 (as of 2018):

swell

Individual evidence

  1. ↑ Lotte Burkhardt: Directory of eponymous plant names - Extended Edition. Part I and II. Botanic Garden and Botanical Museum Berlin , Freie Universität Berlin , Berlin 2018, ISBN 978-3-946292-26-5 doi: 10.3372 / epolist2018 .
  2. ^ Lowiaceae at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed November 25, 2014.
  3. ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z Rafaël Govaerts (Ed.): Orchidantha. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 9, 2018.
  4. ↑ W. John Kress, Chelsea D. Specht: The evolutionary and biogeographic origin and diversification of the tropical monocot or zingiberales. In: Aliso , Volume 22, 2006, pp. 621-632: Online.

Web links

Commons : Orchidantha  - collection of images, videos and audio files