Micromyrtus
Micromyrtus | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Micromyrtus blakelyi at its natural site in Muogamarra Nature Reserve, New South Wales , Australia |
||||||||||||
Systematics | ||||||||||||
|
||||||||||||
Scientific name | ||||||||||||
Micromyrtus | ||||||||||||
Benth. |
Micromyrtus is a genus of plants withinthe myrtle family (Myrtaceae). All up to 44 species are originally only found in Australia and are called "Heath myrtles" there.
description
Appearance and leaves
Micromyrtus species grow as spreading to upright, evergreen shrubs that usually reach heights of 0.4 to 1 (0.3 to 2) meters. They contain essential oils . The above-ground parts of the plant are bare.
The opposite (or cross-opposite) leaves on the branches are at most short-stalked or sessile. The herbaceous or leathery, simple, relatively small leaf blades are dotted with glands (particularly good view of the underside of the leaves) and have an aromatic smell. There are no stipules .
Inflorescences, flowers and pollination
The reduced inflorescences usually contain only one, rarely two or three flowers at most over very short inflorescence shafts in the leaf axils in the upper area of the branches. Each flower stands over a pair of durable or rapidly perishable bracts .
The relatively small, hermaphrodite flowers are mostly radial symmetry and usually five, rarely six-fold with a double flower envelope . The flower cup (hypanthium) that has grown together with the ovary is ribbed or grained. The five or rarely six free, small sepals are membranous or corolla-like with a smooth or fringed edge. The five or rarely six free petals are entire, elliptical, egg or circular and can be nailed. The colors of the petals are yellow or white to pink. The stamens are usually straight in the bud or rarely curved a few inward. Usually five or six more or less identical stamens are arranged in one or two circles . The stamens are all fertile. The thread-like or belt-shaped stamens are free from each other and not fused with the petals. The look-alike dust bag open with longitudinal slots and do not project beyond the petals. There is a discus. Two carpels are one under permanent, single-chamber ovary grown. Two or ten anatropic ovules are arranged in basal to lateral placentation . The stylus ends in a simple scar that does not protrude over the bracts.
The pollination is done by insects ( Entomophilie ) or birds ( ornithophily ).
Fruits and seeds
The dry closing fruits are mostly single-seeded, rarely two- to three-seeded nut fruits . The ellipsoidal to kidney-shaped seeds contain a curved embryo with two cotyledons ( cotyledons ) and there is no endosperm present.
Chromosome number
The basic chromosome number is n = 11. In some species there is diploidy , i.e. 2n = 22; but tetraploidy was also found.
Spread and endangerment
The genus Micromyrtus is distributed with up to 44 species in southern, central and northeastern Australia . Species occur in the Australian states of Western Australia , South Australia , Queensland , New South Wales , Victoria and in the Northern Territory and Australian Capital Territory .
Micromyrtus grandis is rated as "Endangered" = "highly endangered". Micromyrtus blakelyi and Micromyrtus minutiflora are classified as "Vulnerable" = "endangered".
Systematics
The genus Micromyrtus was established in 1865 by George Bentham in G. Bentham & JDHooker: Genera Plantarum , 1, p. 700. Lectotype species is Micromyrtus drummondii Benth. nom. superfl., today this is a synonym of Micromyrtus obovata (Turcz.) JWGreen . The generic name Micromyrtus is made up of the Greek word micro for "small" and myrtus , a genus from the Myrtaceae family. The last partial revision of the genus Micromyrtus took place in BL Rye: A partial revision of the south-western Australian species of Micromyrtus (Myrtaceae: Chamelaucieae) , In: Nuytsia , Volume 16, Issue 1, 2006, pp. 121-122.
The genus Micromyrtus belongs to the tribe Chamelaucieae in the subfamily Myrtoideae within the family of Myrtaceae .
There are up to 44 Micromyrtus species:
- Micromyrtus acuta Rye : It occurs only in the Australian state of Western Australia .
- Micromyrtus albicans A.R.Bean
- Micromyrtus arenicola Rye
- Micromyrtus barbata J.W. Green
- Micromyrtus blakelyi J.W. Green
- Micromyrtus capricornia A.R.Bean
- Micromyrtus carinata A.R.Bean
- Micromyrtus chrysodema Rye
- Micromyrtus ciliata (Sm.) Druce
- Micromyrtus clavata J.W. Green ex Rye
- Micromyrtus collina Rye
- Micromyrtus delicata A.R.Bean
- Micromyrtus elobata (F.Muell.) Benth. : There are two subspecies.
- Micromyrtus erichsenii Hemsl.
- Micromyrtus fimbrisepala J.W.Green
- Micromyrtus flaviflora (F.Muell.) JMBlack
- Micromyrtus forsteri A.R.Bean
- Micromyrtus gracilis A.R.Bean
- Micromyrtus grandis J.T. Hunter
- Micromyrtus greeniana Rye
- Micromyrtus helmsii (F.Muell. & Tate) JWGreen
- Micromyrtus hexamera (Maiden & Betche) Maiden & Betche
- Micromyrtus hymenonema (F.Muell.) CAGardner
- Micromyrtus imbricata Benth.
- Micromyrtus leptocalyx (F.Muell.) Benth.
- Micromyrtus littoralis A.R. Bean
- Micromyrtus minutiflora Benth.
- Micromyrtus monotaxis Rye
- Micromyrtus mucronulata Rye
- Micromyrtus navicularis Rye
- Micromyrtus ninghanensis Rye
- Micromyrtus obovata (Turcz.) JWGreen
- Micromyrtus papillosa J.W. Green ex Rye
- Micromyrtus patula A.R. Bean
- Micromyrtus placoides Rye
- Micromyrtus prochytes Rye
- Micromyrtus racemosa Benth.
- Micromyrtus redita Rye
- Micromyrtus rogeri J.W. Green ex Rye
- Micromyrtus rotundifolia A.R.Bean
- Micromyrtus rubricalyx Rye
- Micromyrtus serrulata J.W. Green
- Micromyrtus sessilis J.W. Green
- Micromyrtus stenocalyx (F.Muell.) JWGreen
- Micromyrtus striata J.W. Green
- Micromyrtus sulphurea W. Fitzg.
- Micromyrtus triptycha Rye
- Micromyrtus trudgenii Rye
- Micromyrtus uniovula Rye
- Micromyrtus vernicosa A.R.Bean
swell
Individual evidence
- ↑ a b c d e Entry in Australian Plant Name Index = APNI. last accessed on January 19, 2013
- ↑ a b c d e f g h i j k l JW Green: Entry in the Electronic Flora of South Australia genus Fact Sheet . last accessed on January 19, 2013
- ↑ a b c d e f g h Peter G. Wilson: Entry in the New South Wales Flora Online . last accessed on January 19, 2013
- ↑ a b c d e f g h i j k l m n o p q r s t u HR Coleman: Entry in the Western Australian Flora , last change 2008. Last accessed on January 19, 2013
- ↑ IPCN Chromosome Reports . last accessed on January 19, 2013
- ↑ EPBC Act List of Threatened Flora . last accessed on January 19, 2013
- ↑ First publication scanned at biodiversitylibrary.org .
- ↑ Micromyrtus at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed January 19, 2013.
- ↑ Micromyrtus in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved January 19, 2013.
- ↑ Rafaël Govaerts (ed.): Micromyrtus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 30, 2020. (last changes adapted from R. Govaerts, N. Sobral, P. Ashton, F. Barrie, BK Holst, LL Landrum, K. Matsumoto, F. Fernanda Mazine, E. Nic Lughadha, C. Proença & al .: World Checklist of Myrtaceae , Kew Publishing, Royal Botanic Gardens, Kew, 2008, pp. 1-455.)
Web links
- Rodger Elliot: Shrubby Myrtles at Australian Plants Online . last accessed on January 17, 2013
Supplementary literature
- JW Green: Thryptomene and Micromyrtus (Myrtaceae) in arid and semi-arid Australia. In: Nuytsia , Volume 3, Issue 2, 1980, pp. 183-205: PDF .