Grusonia species

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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 Reference
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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.
Texas Status
Native
Scientific Name Grusonia grahamii (Opuntia schottii var. grahamii) USDA PLANTS Symbol
GRGR6
Common Name Graham's Dog Cholla ITIS Taxonomic Serial No.
907940
Family Cactaceae (Cactus) SEINet Reference
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Description Habitat: Desert environment; sandy, gravelly dunes, slopes and flats, 2300 to 5000 ft; Chihuahua Desert adjacent to Rio Grande.
Plant: Low, mat-forming cactus, clumps 3 to 4-1/2 inches tall and 3 to 10 ft across; more-or-less cylindrical stems, about 5/8 to 1-3/8 inches in diameter, easily broken at joints.
Spines: Central spines (4 to 7) smooth, straw-colored to brown, often pink- or red-tinged, 3/4 to 1-1/2 inches long, gray with age; radial spines (6 to 8) grayish-white, less than 1/2-inch long, bent downwards.
Inflorescence: Bright yellow flowers opening early afternoon; 2 inches wide; green to yellow filaments and anthers, cream-colored style and pale yellow-green stigma lobes.
Bloom Period: May to June.
Fruit: Yellowish, spineless, cylindric to ellipsoid, 7/8 to 1-3/8 inches long.
References: "Manual of the Vascular Plants of Texas" by Correll and Johnston, "Cacti of Texas" by Powell, Weedin and Powell and SEINet.
Texas Status
Native

© Tom Lebsack 2019