Urochloa arizonica(Scribn. & Merr.) Morrone & Zuloaga

Arizona signalgrass

WFO wfo-0000906789 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Urochloa arizonica, photographed by Daniel
fig. a Daniel, CC0 1.0 / 2021-08-31 / obs. 154454837
Urochloa arizonica, photographed by Dominic Gentilcore
fig. b Dominic Gentilcore, CC BY 4.0 / obs. 153154801
Urochloa arizonica, photographed by Dominic Gentilcore
fig. c Dominic Gentilcore, CC BY 4.0 / obs. 151918044
Urochloa arizonica, photographed by Jared Shorma
fig. d Jared Shorma, CC BY 4.0 / obs. 151570812
Urochloa arizonica, photographed by Jared Shorma
fig. e Jared Shorma, CC BY 4.0 / obs. 172893056
Urochloa arizonica, photographed by Cecelia Alexander
fig. f Cecelia Alexander, CC0 1.0 / obs. 50838588
Urochloa arizonica, photographed by Cecelia Alexander
fig. g Cecelia Alexander, CC0 1.0 / obs. 25260599
Urochloa arizonica, photographed by Cecelia Alexander
fig. h Cecelia Alexander, CC0 1.0 / obs. 23831056

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
Smithsonian, US National Herbarium
Accession
US 3662189
Filed as
Urochloa arizonica (Scribn. & Merr.) Morrone & Zuloaga
Det. by
Poaceae Reorganization Project
Collected
F. J. Santana M. & A. Vazquez 1988-08-19
Origin
MX
The sheet
View the digitised specimen (CC0 1.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 10 botanical countries

Regions where Urochloa arizonica is native: Alabama, Arizona, California, Florida, Mexico Northeast, Mexico Northwest, Mexico Southwest, Mississippi, New Mexico, Texas AlabamaArizonaCaliforniaFloridaMexico NortheastMexico NorthwestMexico SouthwestMississippiNew MexicoTexas
Native distribution of Urochloa arizonica, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Alabama ALA NORTHERN AMERICA
Arizona ARI
California CAL
Florida FLA
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southwest MXS
Mississippi MSI
New Mexico NWM
Texas TEX

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 138 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 0.0 °C 3.8 °C 15.8 °C
Warmest month, mean daily high 31.0 °C 34.9 °C 38.5 °C
Annual rainfall 173 mm 329 mm 494 mm
Rainfall in the driest quarter 2 mm 24 mm 34 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 138 research-grade observations of Urochloa arizonica that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 12 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Brachiaria arizonica (Scribn. & Merr.) S.T.Blake
  • Brachiaria arizonica var. laeviglumis (Scribn. & Merr.) Beetle
  • Brachiaria arizonica var. major (Vasey) Beetle
  • Brachiaria arizonica var. tenuis (Scribn. & Merr.) Beetle
  • Panicum arizonicum Scribn. & Merr.
  • Panicum arizonicum var. dissitiflorum Scribn. & Merr.
  • Panicum arizonicum var. laeviglume Scribn. & Merr.
  • Panicum arizonicum var. majus (Vasey) Scribn. & Merr.
  • Panicum arizonicum var. tenue Scribn. & Merr.
  • Panicum dissitiflorum Vasey ex S.Watson
  • Panicum fasciculatum var. majus (Vasey) Beal
  • Panicum fuscum var. majus Vasey

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.