Microcitrus australis
| Microcitrus australis | ||||||||||||
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| Microcitrus australis | ||||||||||||
| ( Mudie ) Swingle |
Citrus australis is a plant of the genus Microcitrus in the family of Rutaceae (Rutaceae). It is used as an ornamental plant and a fruit tree .
description
Appearance and leaf
Microcitrus australis grows as a tree with heights of 10 to 20 meters. The emerging main shoots grow straight with internodes 1 to 1.5 cm long, the short side shoots are slightly zigzag, here the internodes are only 0.5 to 1 cm long. The branches are angular in cross-section. The thorns stand individually and are 0.5 to 1 cm long on the main shoots, only 0.2 to 0.5 cm on the side shoots.
Young plants only have greatly reduced lower leaves , later small elongated to elliptical leaves develop , which gradually lead to the leaf shape of the adult plant. Their leaves are divided into a leaf blade and a petiole, with a separating tissue between the two. The 2 to 3 mm long petiole is hairy and flattened on the upper side. On thick branches, the leaf blades are 3 to 4 cm long and 2 to 3 cm wide and obovate to obovate. On weak side shoots, the leaves are 2 to 3 cm long and 1.2 to 1.8 cm wide; here they are rhombic in shape. The leaves are hairless, occasionally sparsely ciliate at the base of the leaf. The leaf veins are mainly visible on the underside of the leaf. On each side of the midrib, 12 to 15 leaf veins branch off, which in turn branch off again.
Flower, fruit and seeds
The flowers are solitary in the leaf axils. The hermaphrodite flowers are 1 to 1.5 cm in diameter and are radially symmetrical and four or five-fold. The number of stamens is 16 to 20. The stamens are not grown together.
The fruits are spherical with a diameter of 2.5 to 5 cm. Like other citrus fruits, they can be divided into segments; there are six such segments. The segments in turn are made up of numerous juice sacs, the shape of these juice sacs is characteristic: they are short stalked on the outer wall of the fruit, extend inward in the shape of a cigar and end in a blunt and often irregularly shaped tip. On the outer wall of the fruit they are very light green, and on the inside they are stronger green. The individual juice sacs are 6 to 10 mm long and 2.5 to 3.5 mm wide; in the ripe fruit they all stick together slightly. Their consistency is quite firm - so they can be sliced without their contents leaking. The content consists of sour, green juice and numerous large, yellowish oil droplets. The flattened seed contains only one embryo .
Occurrence
Microcitrus australis is native to the northeast of Australia. The type specimen was collected at Moreton Bay.
Systematics and botanical history
It was first described in 1829 under the name ( Basionym ) Limonia australis by Robert Mudie in The Picture of Australia , p. 151. It was first described in 1915 under the name Microcitrus australis by Walter Tennyson Swingle in Journal of the Washington Academy of Sciences , Volume 5, p 572 placed in the new genus Microcitrus . Another synonym for Microcitrus australis (Mudie) Swingle is Citrus australis (A.Cunn. Ex Mudie) Planch .
The separation of the genus Microcitrus from Citrus means that the latter is no longer monophyletic. More recent studies therefore include Microcitrus again in the genus Citrus and name the plant described here Citrus australis .
Individual evidence
- ↑ a b Microcitrus australis in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
- ↑ a b c d e Walter T. Swingle: The Botany of Citrus and Its Wild Relatives . In: W. Reuther, HJ Webber, LD Batchelor (Ed.): The Citrus Industry . Berkeley 1967 ( ucr.edu ). The Botany of Citrus and Its Wild Relatives ( Memento of the original from July 19, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Randall J. Bayer, David J. Mabberley, Cynthia Morton, Cathy H. Miller, Ish K. Sharma, Bernard E. Pfeil, Sarah Rich, Roberta Hitchcock, Steve Sykes: A molecular phylogeny of the orange subfamily (Rutaceae: Aurantioideae) using nine cpDNA sequences . In: American Journal of Botany . tape 96 , no. 3 , 2009, p. 668-685 .
