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Zygochloa és un gènere de plantes de la família de les poàcies, ordre de les poals, subclasse de les commelínides, classe de les liliòpsides, divisió dels magnoliofitins.
Zygochloa és un gènere de plantes de la família de les poàcies, ordre de les poals, subclasse de les commelínides, classe de les liliòpsides, divisió dels magnoliofitins.
Zygochloa paradoxa ist eine in Australien endemische Grasart und prägt die Grasländer nördlich des Eyre-Sees. Sie ist die einzige Art der Gattung Zygochloa.
Zygochloa ist ein zweihäusiges, ausdauerndes Gras, das dichte Horste bildet. Die Horste werden bis zu 1,5 Meter hoch bei einem Durchmesser von einem Meter. Die Halme können bis 200 Zentimeter hoch werden und sind rohrähnlich mit einem Durchmesser von bis zu acht Millimetern.
Die Blätter sind kurz und werden bei Trockenheit oft abgeworfen. Die Ligula ist ein Haarkranz von einem Millimeter Länge.
Die Blütenstände sind dichte, kugelige Ähren mit kurzen Internodien. Die Ähren sind dimorph und einzeln stehend. Ein Ährchen besteht aus zwei Blüten. Die männlichen Ähren haben ein bis zwei Zentimeter Durchmesser. Ihre Ährchen besitzen zwei männliche Blüten mit je drei Staubblättern, ein Gynoeceum fehlt. Die weiblichen Ähren haben einen Durchmesser von 2,5 bis 3,5 Zentimetern. In ihren Ährchen ist die untere Blüte steril, die obere besitzt Staminodien und einen Fruchtknoten mit langem, schlanken Griffel und gefiederter Narbe.
Die Art ist in Australien endemisch. Sie kommt vor allem im ariden Inneren nördlich des Lake Eyre vor. Es bewächst vor allem die Sanddünen, etwa der Simpsonwüste.
Zygochloa paradoxa ist eine in Australien endemische Grasart und prägt die Grasländer nördlich des Eyre-Sees. Sie ist die einzige Art der Gattung Zygochloa.
Zygochloa is a genus of desert plants in the grass family known only from Australia.[2][3][4][5] The only known species is Zygochloa paradoxa, commonly known as sandhill canegrass. It occurs in extremely arid areas such as the Simpson Desert.[1][6][7]
Zygochloa paradoxa is a dense, green, bushy perennial 1.5 m (4 ft 11 in) tall, 1 m (3 ft 3 in) wide, that forms tussocks or hummocks. Male and female flowers are found on different plants (dioecious). The plant has a rhizomatous stem that usually grows horizontally and has coarse roots .[2][8]
The stem bearing the flowers (inflorescence), or culm, is hard and brittle with a shallow channel, up to at least 8 mm (0.31 in) in diameter and 40 cm (16 in) to 150 cm (59 in) tall, cylindrical or somewhat angled.[9] Leaf-blades 1 cm (0.39 in) to 30 cm (12 in) long and 1 mm (0.039 in) to 10 mm (0.39 in) wide.
There are two types of flowers. The first type are male heads globular in shape, 1 cm (0.39 in) to 2 cm (0.79 in) in diameter. The second type are female heads which are also globular in shape, 2.5 cm (0.98 in) to 3.5 cm (1.4 in) in diameter, with the prominent chaffy bract like structures (bracteoles) having rigid tips. Male spikelet with no stem (sessile), 6 mm (0.24 in) to 8 mm (0.31 in) long. Female spikelets are solitary and having a short stem (pedicellate), 6 mm (0.24 in) to 10 mm (0.39 in) long.[8]
Flowers mostly March to September.
Zygochloa paradoxa was first described by the botanist Robert Brown as Neurachne paradoxa in 1849.[10] The type specimen was collected by Charles Sturt during his expedition into Central Australia (1844 to 1846), and is held by the Natural History Museum, London.[11] Brown observed that the identification of the species was based on a single specimen which was imperfect in its leaves and stem, however, had sufficient fruits. Brown noted that the specimen differs materially in habit from the original species Neurachne alopeuroides, as well as from Neurachne mitchelliana. No location details were provided, but was likely to have been collected from near the junction of the borders of New South Wales, South Australia and Queensland.[2]
In 1874, Ferdinand Mueller moved the species to the genus Panicum and published a replacement name (nomen novum) Panicum pseudoneurachne, on the basis of the smooth hardened fruiting glume and palea.[12]
Bentham proposed a new combination Spinifex paradoxa in 1877.[13] Bentham thought that Mueller had overlooked the dioecious character of the plant, and taking into account the inflorescence being head-shaped (capitate), appeared to belong to the genus Spinifex. However, Bentham did note the discrepancy from Spinifex due to the small size of spikelets and the lack of long spines.
Blake moved the species to a new genus Zygochloa in 1941, identifying a number of key differences between the plant and Spinifex genus.[2] Firstly, Blake noted that inflorescences in Spinifex are less densely head-shaped and considerably larger. Secondly, the extension of the peduncle in Spinifex into a very long, rigid tapering spine. Finally, in Spinifex the mature flowers disarticulate in their entirety from the plant, while in Zygochloa the heads appear to break up. Zygochloa paradoxa is the current accepted name for the species.
When Blake described the genus Zygochloa, he derived the name from Greek zygon (ζυγόν) meaning pair or yoke, and chloa (Xλόα) meaning grass. The name refers to the dioecious character of the species.[2] Paradoxa is from the Greek para meaning irregular, and doxa meaning opinion. The plant is different from the expected in regard to related species. [9]
Zygochloa is a genus of desert plants in the grass family known only from Australia. The only known species is Zygochloa paradoxa, commonly known as sandhill canegrass. It occurs in extremely arid areas such as the Simpson Desert.
Zygochloa es un género monotípico de plantas herbáceas de la familia de las gramíneas o poáceas.[1] Su única especie: Zygochloa paradoxa (R.Br.) S.T.Blake 1941, es originaria de Australia.
Es una planta robusta, perenne, rizomatosa y dioica, formando matas o montículos de 1,5 m de altura, 1 m de ancho. Culmos duros, frágiles, de hasta 8 mm o más de diámetro. Lígula una hilera de pelos de 1 mm de largo; escasa hoja, rígida y plana, con nervios prominentes. Inflorescencia de dos tipos: Cabezas masculinas globulares, diámetro de 1-2 cm, la femenina también globular, de 2.5-3.5 cm de diámetro, las brácteas prominentes con puntas rígidas. Espiguillas dimorfas, unisexuales, ligeramente comprimidas. Espiguillas masculinas poco pediceladas, 6-8 mm de largo, algunos en una panícula punta-como, con 2 flósculos masculinos; glumas subiguales, rígidas, 5-7-nervada, lemas tiesos con márgenes translúcidos, pálea rígida. Espiguillas femeninas 6-10 mm de largo, solitarias, poco pediceladas, sostenidas por brácteas membranosas.[2]
Zygochloa paradoxa fue descrita por (R.Br.) S.T.Blake y publicado en Papers from the Department of Biology, University of Queensland Papers 1(19): 7–8, t. 3. 1941.[3]
Zygochloa es un género monotípico de plantas herbáceas de la familia de las gramíneas o poáceas. Su única especie: Zygochloa paradoxa (R.Br.) S.T.Blake 1941, es originaria de Australia.
Zygochloa paradoxa est une espèce de plantes de la famille des Poaceae (graminées), sous-famille des Panicoideae , endémique d'Australie où elle pousse dans les régions très arides comme le désert de Simpson. C'est la seule espèce du genre monotypique Zygochloa.
Ce sont des plantes vivaces, dioïques, rhizomateuses, aux rhizomes allongés et aux tiges (chaumes) ligneuses, géniculées ascendantes, pouvant atteindre 1,5 m de long et 8 cm de diamètre.
Selon Catalogue of Life (6 juillet 2017)[2] :
Zygochloa paradoxa est une espèce de plantes de la famille des Poaceae (graminées), sous-famille des Panicoideae , endémique d'Australie où elle pousse dans les régions très arides comme le désert de Simpson. C'est la seule espèce du genre monotypique Zygochloa.
Ce sont des plantes vivaces, dioïques, rhizomateuses, aux rhizomes allongés et aux tiges (chaumes) ligneuses, géniculées ascendantes, pouvant atteindre 1,5 m de long et 8 cm de diamètre.
Zygochloa is een monotypisch geslacht uit de grassenfamilie (Poaceae) en is endemisch in Australië. De enige soort is Zygochloa paradoxa. Het komt in extreem droge gebieden voor zoals de Simpsonwoestijn.
Bronnen Zygochloa é um género botânico pertencente à família Poaceae[1].
Zygochloa paradoxa là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (R.Br.) S.T.Blake miêu tả khoa học đầu tiên năm 1941.[1]
Zygochloa paradoxa là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (R.Br.) S.T.Blake miêu tả khoa học đầu tiên năm 1941.
