Cactus (Cactaceae) family
saguaro cactus (Carnegiea gigantea) -- in March -- Organ Pipe Cactus National Monument, AZ white & cream AZ-SRN
Wiggins' cholla (Cylindropuntia echinocarpa) -- in March -- U.S. 95 in southern Nevada red & pink NV-S
Wiggins' cholla (Cylindropuntia echinocarpa) -- in March -- Cabeza Prieta National Wildlife Refuge, southern Arizona
jumping cholla (Cylindropuntia fulgida) -- in March -- Sonoran Desert National Monument, AZ green & brown AZ-S
jumping cholla (Cylindropuntia fulgida) -- in March -- Organ Pipe Cactus National Monument, AZ
tree cholla (Cylindropuntia imbricata) -- in March -- near Walsenberg, CO red & pink CO-G
tree cholla (Cylindropuntia imbricata) -- in April -- Mills Canyon, Kiowa National Grassland, NM red & pink NM-N
walkingstick cactus (Cylindropuntia spinosior) -- in April -- Villanueva State Park, NM red & pink NM-N
whipple cactus (Cylindropuntia whipplei) -- in March -- Four Corners, NM green & brown NM-N
cottontop cactus (Echinocactus polycephalus) -- in March -- Death Valley National Park, CA yellow & orange
Texas claret-cup cactus (Echinocereus coccineus var. paucispinus) -- in March -- San Xavier Mission, AZ red & pink
Texas claret-cup cactus (Echinocereus coccineus var. paucispinus -- in April -- Big Bend Ranch State Park, TX red & pink
spiny hedgehog cactus (Echinocereus dasyacanthus) -- in April -- Big Bend Ranch State Park, TX red & pink
Englemann's hedgehog cactus (Echinocereus englemannii) -- in March -- Organ Pipe Cactus National Monument, AZ red & pink AZ-SRN
strawberry hedgehog cactus (Echinocereus enneacanthus) -- in April -- Big Bend National Park, Texas red & pink
Mojave kingcup cactus (Echinocereus mojavensis) -- in May -- Canyons of the Ancients National Monument, CO red & pink
Mojave kingcup cactus (Echinocereus mojavensis) -- in May -- Yampa Bench Road, Dinosaur National Monument, CO red & pink
strawberry cactus (Echinocereus stramineus var. stramineus) -- in April -- Big Bend Ranch State Park, TX red & pink
hen-and-chickens (Echinocereus viridiflorus) -- in June -- South Valley Loop Trail, Lory State Park, CO green & brown CO-LSP
hen-and-chickens (Echinocereus viridiflorus) -- in May -- Pawnee National Grassland, CO
nylon hedgehog cactus (Echinocereus viridiflorus var. chloranthus) -- in April -- Chihuahuan Desert NC green & brown TX-W
Correll's hedgehog (Echinocereus viridiflorus var. correllii) -- in April -- Chihuahuan Desert NC, TX green & brown TX-W
small-flowered hedgehog (Echinocereus viridiflorus var. cylindricus) -- in April -- Chihuahuan Desert NC green & brown TX-W
rusty hedgehog cactus (Echinocereus viridiflorus var. russanthus) -- in April -- Chisos Mts., Big Bend National Park, TX red & pink
Hester's pincushion cactus (Escobaria hesteri) -- in April -- Chihuahuan Desert Nature Center, TX red & pink TX-W
nipple cactus (Escobaria missouriensis) -- in May -- Mill Creek Link Trail, Lory State Park, CO green & brown CO-LSP
spinystar (Escobaria vivipara) -- in June -- Mt. Margaret, Red Feather Lakes Area, CO red & pink CO-M
California barrel cactus (Ferocactus cylindraceus) -- in March -- Organ Pipe Cactus National Monument, AZ yellow & orange AZ-S
glaucous barrel cactus (Ferocactus glauescens) -- in April -- Chihuahuan Desert Nature Center, TX yellow & orange TX-W
fishhook barrel cactus (Ferocactus wislizenii) -- in July -- Bosque del Apache National Wildlife Refuge, AZ yellow & orange NM-S
Mexican lime cactus (Ferocactus pilosus) -- in April -- Chihuahuan Desert Nature Center, TX yellow & orange TX-W
Wright's fishhook cactus (Glandulicactus wrightii) -- in April -- Chihuahuan Desert Nature Center, TX red & pink TX-W
cholla organillo (Grusonia bradtiana) -- in April -- Big Bend Ranch State Park, TX yellow & orange TX-BBR
little nipple cactus (Mammillaria meiacantha) -- in April -- Chihuahuan Desert Nature Center, TX green & brown TX-W
corkseed cactus (Mammillaria tetrancistra) -- in April -- Palm Canyon, Kofa National Wildlife Refuge, AZ red & pink AZ-S
Chihuahuan beehive (Neolloydia conoidea) -- in April -- Chihuahuan Desert Nature Center, TX red & pink TX-W
buckhorn cholla (Opuntia acanthocarpa) -- in March -- Organ Pipe Cactus National Monument, AZ red & pink AZ-SRN
Big Bend pricklypear (Opuntia aggeria) -- in April -- River Road East, Big Bend National Park, TX yellow & orange TX-BB
Big Bend purplish pricklypear (Opuntia azurea var. parva) -- in April -- Big Bend National Park, TX yellow & orange TX-BB
purple pricklypear (Opuntia azurea) -- in April -- Big Bend National Park, Texas yellow & orange
beavertail pricklypear (Opuntia basilaris) -- in March -- Palo Verde, CA red & pink CA-S
beavertail pricklypear (Opuntia basilaris) -- in March -- Death Valley National Park, CA CA-DVNP
teddy-bear cholla (Opuntia bigelovii) -- in January -- Joshua Tree National Park, CA green & brown CA-S
Big Bend devil cholla (Opuntia densispina) -- in April -- River Road East, Big Bend National Park, Texas yellow & orange TX-BB
sweet prickly pear (Opuntia dulcis) -- in April -- River Road East, Big Bend National Park, Texas yellow & orange TX-BB
Christmas cholla (Opuntia leptocaulis) -- in April -- Big Bend Ranch State Park, TX yellow & orange TX-BBR
bigroot pricklypear (Opuntia macrorhiza) -- in June -- Horsetooth Reservoir, Larimer County Open Space, CO
bigroot pricklypear (Opuntia macrorhiza) -- in July -- National Center for Atmospheric Research, Boulder, CO
bigroot pricklypear (Opuntia macrorhiza) -- in November -- Gateway Natural Area, Fort Collins, Larimer County, CO
glochids at 20 x magnification
bigroot pricklypear (Opuntia macrorhiza) -- in December -- Bellvue, Larimer County, CO
tulip pricklypear (Opuntia phaeacantha) -- in May -- Canyons of the Ancients National Monument, CO yellow & orange
tulip pricklypear (Opuntia phaeacantha) -- in April -- Big Bend Ranch State Park, TX yellow & orange
plains pricklypear (Opuntia polyacantha) -- in June -- Hall Ranch Open Space, Boulder County, CO
plains pricklypear (Opuntia polyacantha) -- in July -- Young Gulch, Poudre Canyon, Larimer County, CO
plains pricklypear (Opuntia polyacantha) -- in June -- Cherokee Park State Wildlife Area, CO yellow & orange CHER
plains pricklypear (Opuntia polyacantha) -- in June -- Pawnee National Grassland, CO red & pink CO-G
starvation pricklypear (Opuntia polyacantha var. polyacantha) -- in May -- Overlook Trail, Lory State Park, CO yellow & orange OT-LSP
starvation pricklypear (Opuntia polyacantha var. polyacantha) -- in June, Wray, Yuma County, CO
spiny-fruited pricklypear (Opuntia spinosibacca) -- in April -- Big Bend National Park, TX red & pink TX-BB
mountain ball cactus (Pediocactus simpsonii) -- in May -- Sand Creek National Landmark WY-SC
organ pipe cactus (Stenocereus thurberi) -- in March -- Organ Pipe Cactus National Monument, AZ white & cream AZ-SRN