Grusonia aggeria

(Clumped Dog Cholla)


Grusonia aggeria, Cerro Castelan, Big Bend National Park 4572


Grusonia aggeria, Cerro Castelan, Big Bend National Park 4571


Grusonia aggeria, Cerro Castelan, Big Bend National Park 4576

Scientific Name Grusonia aggeria (Opuntia aggeria) USDA PLANTS Symbol GRAG3
Common Name Clumped Dog Cholla, Jumping Dog Cholla ITIS Taxonomic Serial No. 907938
Family Cactaceae (Cactus) SEINet
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Description Habitat: Desert environment; gravelly to silty soils in flats and slopes in Chihuahua Desert (Big Bend area) from 1800 to 3500 ft.
Plant: Low, mat-forming cactus, less than 4 inches tall; more-or-less cylindrical stems, narrower at base; stems prostrate around edges and upright near the center; firm joints.
Spines: Central spines (3 to 4) usually grayish-white, may be reddish-brown, 1-1/4 to 3-1/2 inches long, longer ones often twisted or curved; radial spines (2 to 4) grayish-white, 1/4 to 1 inch long, bent downwards.
Inflorescence: Bright yellow flowers opening around noon for a single day; 1-1/2 to 2 inches wide and 2 to 2-3/4 inches long; yellow-orange to reddish filaments, yellow to cream anthers, cream-colored style and pale-green/yellow stigma lobes.
Bloom Period: March to May.
Fruit: Pale yellow, aging to gray, spineless, cylindric to ellipsoid, 3/4 to 1 inch long.
References: "Little Big Bend" by Roy Morey, "Cacti of Texas" by Powell, Weedin and Powell and SEINet.
BONAP Distribution Map

Map Color Key
Texas Status:

Banner photo of Castilleja indivisa and Lupinus ssp. taken along FM 1323 north of Johnson City, Blanco County

© Tom Lebsack 2024