Gyrostemonaceae

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Gyrostemonaceae
Gyrostemon ramulosus, illustration

Gyrostemon ramulosus , illustration

Systematics
Eudicotyledons
Nuclear eudicotyledons
Rosids
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Gyrostemonaceae
Scientific name
Gyrostemonaceae
Final

The Gyrostemonaceae are a family of plants in the order of the cruciferous (Brassicales). The 16 to 19 species are native to Australia including Tasmania (a species).

description

Vegetative characteristics

You grow as shrubs , small trees or sometimes semi-shrubs , the xerophytes are often somewhat succulent are. The secondary growth in thickness is based on a conventional cambium ring . The trunks and leaves are rubbery.

The alternate and spirally arranged leaves can be stalked or sessile and small to medium-sized. The simple, often fleshy or herbaceous to leathery leaf blades are linear, lanceolate, obovate or ovate. The leaf blades have only one leaf vein or there is pinnate veins . Tiny stipules may be present.

Generative characteristics

The flowers are solitary or in terminal or lateral, racemose or spike-like inflorescences. They are small bracts (Brakteolen) available.

The flowers are functionally unisexual, mostly on separate plant specimens ( diocyte ); the species are seldom single-sexed ( monoecia ). The inconspicuous flowers are more or less radial symmetry . The flower sleeve (Perianth) consists of a circle with four or five intergrown, sepal-like (sepalinen) bloom cladding that a wide fleshy, flat or convex flowers floor surrounded. The calyx is cup-shaped, lobed or entire. The 6 to 100 (numerous) stamens and the ovary are attached to this. The stamens are free from each other and also not fused with the bloom cladding sheets. There are extremely short stamens. The dust bags open with a longitudinal slit. The pollen grains have three apertures and are mostly colpat. 5 to 25 carpels are partially or completely fused to form an upper ovary. There is one anatropic ovule per carpel .

The mostly initially fleshy split fruits break up radially into 2 to 25 single-seeded partial fruits or closing fruits stand together in a collective fruit (syncarp). The seeds have an oily endosperm and a well-developed, curved embryo with two flat cotyledons ( cotyledons ).

Chromosome numbers and ingredients

The chromosome numbers are n = 14 or 15.

The mustard oil glycosides characteristic of the Brassicales order are present in this family .

ecology

The pollination is carried by the wind ( anemophily ).

Occurrence

The Gyrostemonaceae family is native to large areas of Australia and occurs throughout the continent , with the exception of the monsoon-affected north and southwestern Tasmania. However, the species only occur more frequently in arid areas. Some species are “fire opportunists” and colonize disturbed locations.

Systematics

The Gyrostemonaceae family is the sister group of the Resedaceae within the order of the cruciferous (Brassicales) .

In the family Gyrostemonaceae there are four to five genera with 16 to 19 species:

supporting documents

The article is based on the following web links:

Individual evidence

  1. ^ Codonocarpus at Australian Plant Name Index .
  2. ^ Australian Plant Name Index .
  3. Gyrostemon at Australian Plant Name Index .
  4. ^ Australian Plant Name Index .
  5. Katherine S. Downes, Byron B. Lamont, Marnie E. Light & Johannes van Staden: The fire ephemeral Tersonia cyathiflora (Gyrostemonaceae) germinates in response to smoke but not the butenolide 3-methyl-2H-furo [2,3-c ] pyran-2-one , In: Annals of Botany , Volume 106, Issue 2, 2010, pp. 381-384.
  6. ^ GJ Keighery: Walteranthus, a new genus of Gyrostemonaceae from Western Australia , In: Botanische Jahrbucher ... , Volume 106, 1, Engelmann Leipzig 1985.
  7. ^ Australian Plant Name Index .

Web links

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