Zygochloa

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Sandhill canegrass
Zygochloa paradoxa habit 2.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Panicoideae
Supertribe: Panicodae
Tribe: Paniceae
Subtribe: Cenchrinae
Genus: Zygochloa
S.T.Blake
Species:
Z. paradoxa
Binomial name
Zygochloa paradoxa
Synonyms [1]
  • Neurachne paradoxaR.Br.
  • Panicum pseudoneurachneF.Muell.
  • Spinifex paradoxus(R.Br.) Benth.

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]

Contents

Description

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.

Taxonomy

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 von 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.

Etymology

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]

Related Research Articles

<i>Panicum</i> Genus of grasses

Panicum (panicgrass) is a large genus of about 450 species of Poaceae grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone. They are often large, annual or perennial grasses, growing to 1–3 m (3–10 ft) tall.

<i>Banksia sphaerocarpa</i> Shrub or tree in the family Proteaceae widely distributed across the southwest of Western Australia

Banksia sphaerocarpa, commonly known as the fox banksia or round-fruit banksia, is a species of shrub or tree in the plant genus Banksia. It is generally encountered as a 1–2 m (3.3–6.6 ft) high shrub, and is usually smaller in the north of its range. This species has narrow green leaves, and brownish, orange or yellow round flower spikes which may be seen from January to July. It is widely distributed across the southwest of Western Australia, growing exclusively in sandy soils. It is usually the dominant plant in scrubland or low woodland. It is pollinated by, and is a food source for, birds, mammals, and insects.

<i>Isopogon anemonifolius</i> Shrub of the family Proteaceae

Isopogon anemonifolius, commonly known as broad-leaved drumsticks, is a shrub of the family Proteaceae that is native only to eastern New South Wales in Australia. It occurs naturally in woodland, open forest, and heathland on sandstone soils. I. anemonifolius usually ranges between one and two metres in height, and is generally smaller in exposed heathland. Its leaves are divided and narrow, though broader than those of the related Isopogon anethifolius, and have a purplish tinge during the cooler months. The yellow flowers appear during late spring or early summer and are displayed prominently. They are followed by round grey cones, which give the plant its common name drumsticks. The small hairy seeds are found in the old flower parts.

<i>Rhynchospora alba</i> Species of plant

Rhynchospora alba, the white beak-sedge, is a plant in the sedge family, Cyperaceae. It is a tufted herbaceous perennial around 50 cm tall, with white inflorescences that flower in August. The fruit of the sedge is a small achene with a characteristic beak-like cap. It is dispersed by wind or falls by gravity, leading to individuals existing in tight clumps. The species favours wet, acidic and nutrient poor soils, thriving in Sphagnum-dominated bogs, but also peaty grasslands. As such, it is often used as a positive indicator for bog and mire ecosystem health.

<i>Allolepis</i> Genus of flowering plants

Allolepis is a genus of North American plants in the grass family.

<i>Elaeocarpus bancroftii</i> Species tree in the family Elaeocarpaceae endemic to Queensland, Australia

Elaeocarpus bancroftii, commonly known as Kuranda quandong, Johnstone River almond, ebony heart, grey nut, or nut tree is a large rainforest tree in the family Elaeocarpaceae which is endemic to Queensland. It has coriaceous leaves, attractive white flowers and relatively large fruit containing an edible kernel.

<i>Atractocarpus fitzalanii</i> Species of plant in the family Rubiaceae

Atractocarpus fitzalanii, commonly known as the brown gardenia or yellow mangosteen, is a species of plant in the coffee and madder family Rubiaceae. It is found in coastal parts of tropical Queensland, Australia. The beautifully scented flowers and glossy foliage has seen this plant enter cultivation in gardens of eastern Australia.

<i>Neurachne</i> Genus of Australian grasses

Neurachne, commonly called mulga grass, is a genus of Australian plants in the grass family.

<i>Hakea chordophylla</i> Species of shrub or small tree in the family Proteaceae from central and northern Australia

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<i>Acacia burkittii</i> Species of legume

Acacia burkittii is a species of wattle endemic to Western Australia, South Australia and western New South Wales, where it is found in arid zones, and is a perennial shrub in the family Fabaceae. Common names for it include Burkitt's wattle, fine leaf jam, gunderbluey, pin bush and sandhill wattle. It has also been introduced into India. Previously this species was referred to as Acacia acuminata subsp. burkittii, but is now considered to be a separate species. Grows in mallee, eucalypt and mulga woodland or shrubland, often on sandhills.

<i>Acacia ancistrocarpa</i> Species of legume

Acacia ancistrocarpa, commonly known as Fitzroy wattle, is a shrub belonging to the genus Acacia and the subgenus Juliflorae. The shrub is also known as fish hook wattle, pindan wattle and shiny leaved wattle.

<i>Acacia arida</i> Species of legume

Acacia arida, commonly known as arid wattle or false melaleuca, is a shrub belonging to the genus Acacia and the subgenus Juliflorae native to Western Australia.

<i>Acacia rhodophloia</i> Species of legume

Acacia rhodophloia, commonly known as minni ritchi or western red mulga, is a tree or shrub belonging to the genus Acacia and the subgenus Juliflorae that is endemic to a large area of arid central western Australia. The Indigenous group the Kurrama peoples know the plant as mantaru.

<i>Acacia dictyophleba</i> Species of plant

Acacia dictyophleba, also known as the sandhill wattle, waxy wattlefeather veined wattle, and spear tree, is a shrub belonging to the genus Acacia and the subgenus Phyllodineae. The Nyangumarta peoples know the plant as Langkur or Lungkun; the Thalanyji know it as Jabandi; and the Pintupi know it as mulyati.

<i>Lomandra multiflora</i> Species of plant in Asparagaceae family

Lomandra multiflora, also commonly known as many-flowered mat rush, mat rush and many flowered mat-lily, is a perennial, rhizomatous herb found in Australia and Papua New Guinea. The mat rush is distributed widely in the region and common within its preferred growing conditions. Its conservation status is considered not to be of concern and risk.

Cyperus rigidellus is a sedge of the family Cyperaceae that is native to Australia.

<i>Solanum sturtianum</i> Species of plant

Solanum sturtianum, commonly known as Thargomindah nightshade, is a flowering plant in the family Solanaceae. It is an upright shrub with grey-green leaves and purple flowers. This species is endemic to Australia.

<i>Alpinia arctiflora</i> Species of plant in the family Zingiberaceae

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<i>Atractocarpus sessilis</i> Species of plant in the family Rubiaceae

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<i>Eurychorda</i> Genus of flowering plants

Eurychorda is a monotypic genus of flowering plants in the family Restionaceae formally described in 1998. The only known species, Eurychorda complanata, commonly known as the flat cord-rush, is endemic to Australia. It is characterised by flattened stems and reduced, sheathing leaves.

References

  1. 1 2 Kew World Checklist of Selected Plant Families
  2. 1 2 3 4 5 Blake, Stanley Thatcher (1941). "New Genera of Australian Grasses". University of Queensland Papers, Department of Biology. 1 (19): 1–12, 3 plates.
  3. Tropicos, Zygochloa S.T. Blake
  4. Ausgrass2, Grasses of Australia, Zygochloa
  5. Watson, L., and Dallwitz, M.J. 1992 onwards. The grass genera of the world Archived November 1, 2006, at the Wayback Machine : descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 28 November 2005
  6. The Plant List Zygochloa paradoxa (R.Br.) S.T.Blake
  7. Atlas of Living Australia
  8. 1 2 "Zygochloa paradoxa". PlantNET - NSW Flora Online. Retrieved 8 May 2023.
  9. 1 2 "AusGrass: Grasses of Australia". Australian Biological Resources Study, Canberra, and the Environmental Protection Agency, Queensland. 2002. Retrieved 8 May 2023.
  10. Brown, Robert; Sturt, Charles (1849). Botanical Appendix to Captain Sturt's Expedition into Central Australia. London: G. Norman.
  11. "Data Portal - BM000795783". Natural History Museum, London. Retrieved 9 May 2023.
  12. Mueller, Ferdinand (1874). Fragmenta Phytographiae Australiae. Vol. 8. Melbourne: Auctoritate Gubern. Coloniae Victoriae, Ex Officina Joannis Ferres, 1858-82. doi:10.5962/bhl.title.287.
  13. Bentham, George (1877). Icones plantarum or figures, with brief descriptive characters and remarks, of new or rare plants, selected from the author's herbarium. Vol. 13. London: Longman, Rees, Orme, Brown, Green, & Longman, etc, 1837. doi:10.5962/bhl.title.16059.