Tragus (plant)

Tragus
Tragus australianus
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Chloridoideae
Tribe: Cynodonteae
Subtribe: Traginae
Genus: Tragus
Haller 1768 not Panz. 1813
Type species
Tragus racemosus
(L.) All.
Synonyms[1]
  • Lappago Schreb.
  • Nazia Adans.
  • Echisachys Neck.
  • Echinanthus Cerv.

Tragus, commonly called bur gras,[2] burr grass or carrot-seed grass, is a genus of plants in the grass family. It is native to Africa, Australia, and Eurasia with several species on islands in the Atlantic, Indian, and Pacific Oceans plus one species in Argentina.[3][4][5]

Plants are monoecious, stoloniferous, and either annual or perennial depending on the species. The genus has been introduced in subtropical and tropical areas around the world as weeds of disturbed areas. The culms (stems) are ascending or low and mat forming, glabrous, and circular in cross-section. Blades are flat or folded and linear, ligules membraneous and trichomatous. Flowers are born in narrow panicles; the primary branches are spirally arranged, each possessing 2-5 spikelets; each of these spikelets bears a single floret. Each floret has 3 stamens, the anthers of which are pale yellow. The caryopses (grains) are elliptical and golden-brown.[6][7][8]

Four species of Tragus have been introduced to North America: T. australianus, T. berteronianus, T. heptaneuron, and T. racemosus.[9] The natural chromosome count is 2n = 20 in T. berteronianus, and 2n = 40 in T. racemosus.[10] Tragus species utilize C4 photosynthesis. They prevent erosion, but make for poor grazing and in larger numbers indicate overgrazing.[11]

Species[1][12]
formerly included[1]

several species now regarded as better suited to other genera: Brachypodium Bromus Festuca Leptothrium Lolium Pseudechinolaena

References

[edit]
  1. ^ a b c Kew World Checklist of Selected Plant Families
  2. ^ USDA, NRCS (n.d.). "​Tragus​". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 14 December 2015.
  3. ^ Haller, Albrecht von. 1768. Historia Stirpium Indigenarum Helvetiae Inchoata 2: 203
  4. ^ Tropicos, Tragus Haller
  5. ^ Ausgrass2, Grasses of Australia
  6. ^ "RLEM 610 grass taxonomy tragus". Archived from the original on 2008-05-16. Retrieved 2008-02-23.
  7. ^ Flora of China, Vol. 22 Page 495 锋芒草属 feng mang cao shu Tragus Haller, Hist. Stirp. Helv. 2: 203. 1768.
  8. ^ Altervista Flora Italiana, Lappola, European Bur Grass, Klettengras, Tragus à grappes, Carretes, Tragus Archived 2015-02-01 at the Wayback Machine includes photos and distribution maps
  9. ^ Biota of North America Program 2013 county distribution maps
  10. ^ "Archived copy". Archived from the original on 2010-06-26. Retrieved 2008-02-23.{{cite web}}: CS1 maint: archived copy as title (link)
  11. ^ Tragus koelerioides
  12. ^ The Plant List search for Tragus
[edit]

Media related to Tragus at Wikimedia Commons Data related to Tragus at Wikispecies