Zyzyura mayana
| Zyzyura mayana | ||||||||||||
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Flower heads of Zyzyura mayana |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Zyzyura | ||||||||||||
| H.Rob. & Pruski | ||||||||||||
| Scientific name of the species | ||||||||||||
| Zyzyura mayana | ||||||||||||
| ( Pruski ) H.Rob. & Pruski |
Zyzyura mayana is the only kind of monotypic genus Zyzyura within the family of the daisy family (Asteraceae). It is only known from one site in Belize .
description
Appearance and leaf
Zyzyura mayana is an epilithic , lying, herbaceous plant . It forms roots on the lowest nodes of the hollow stalk . The prostrate, 5 to 20 centimeter long part of the stem has short internodes and is usually bare. The ascending, 15 to 30 centimeter long part forms long internodes at the base and is sparsely hairy.
The opposite arranged leaves are divided into a petiole and a leaf blade. The petiole is usually 3 to 5 millimeters long. The leaf blade is lobed with a length and a width of 4 to 7 millimeters in outline triangular and three to seven times, with the indentations 1/3 to 1/2 to the central rib extend to the edge. The upper side of the leaf is sparsely hairy, while the paler underside of the leaf is glabrous and dotted with glands. The leaf margin is more or less truncated at the base of the blade while it is slightly notched on the leaf lobes.
Inflorescence, flower and fruit
The total inflorescences standing at the end of the ascending stems contain three to ten cup-shaped partial inflorescences . The inflorescence shaft is usually 0.5 to 1.8 inches long. The few and very small bracts of the flower heads are arranged opposite to almost opposite. The flower heads are disc-shaped, wide-hemispherical, with a height and a diameter of up to 7 millimeters. The involucre containing mostly in two rows arranged about 16 almost the same, parchment-like and at the upper end more trockenhäutig expectant husks , which are obovate to blunt pointed top end; a few outermost bracts are shorter and spread out in fully developed flower heads. The high-conical bottom of the cup is hollow on the inside. There are no chaff leaves.
Each flower head contains 20 to 23 tubular flowers . The white, mostly bare tubular flowers are 2.2 to 2.3 millimeters long and lobed. The thickly ribbed corolla tube is wider at its base than in the upper area where it fits closely to the stylus. The triangular shaped corolla lobes are sparsely dotted with glands. The counter dust bags are about 0.5 millimeters long. The pollen is in a liquid and is around 18 micrometers in size. The stylus is and its base densely papillae or hairy and has thickened appendages.
The three- to five-ribbed achenes are approximately spindle-shaped with a length of 1.2 to 1.3 millimeters. The pappus has about ten durable cardboard bristles.
Occurrence
Zyzyura mayana has only been at the scene of the type of copy on the Victoria Peak , in the in Belize situated Maya Mountains found. There Zyzyura mayana grows on rocks.
Systematics
It was first described as Fleischmannia mayana in 2012 by John Francis Pruski in Phytoneuron , number 32, page 6. In 2013, Harold Ernest Robinson and John Francis Pruski transferred this species in PhytoKeys , number 20, page 3 as Zyzyura mayana into the newly established, monotypic Genus Zyzyura . The generic name Zyzyura is chosen arbitrarily and, according to its author, has no special meaning.
Zyzyura mayana is the only species of the genus Zyzyura from the tribe Eupatorieae in the subfamily Asteroideae within the family Asteraceae .
swell
- Harold Robinson, John F. Pruski: Zyzyura, a new genus of Eupatorieae (Asteraceae) from Belize . In: PhytoKeys . No. 20 , 2013, ISSN 1314-2003 , p. 1-7 , doi : 10.3897 / phytokeys.20.4033 .
Individual evidence
- ↑ a b c d e f g h Harold Robinson, John F. Pruski: Zyzyura, a new genus of Eupatorieae (Asteraceae) from Belize . In: PhytoKeys . No. 20 , 2013, ISSN 1314-2003 , p. 1-7 , doi : 10.3897 / phytokeys.20.4033 .
- ↑ Fleischmannia mayana. In: The International Plant Names Index. www.ipni.org, accessed January 31, 2013 (English).
