Opuntia nicholii

This is a large form of O.polyacantha, occurring around Glen Canyon - Marble Canyon area on Colorado River.

Sclerocactus parviflorus

This almost white flower comes from the population where white and pink flowering plants, with spines from brown-red to pure white are growing together.

Sclerocactus whipplei 'rosei'

Sclerocactus whipplei is known to have yellow flowers. This pink-flowering plant makes it very confusing, but if you look closely you see the distinct upward-pointing flat white spine, characteristic to the species. It is well seen on original 1856 illsutration by Paulus Roetter stored in National Museum of Natural History  (click the link to see).
The pictured plant is probably as small as those plants can flower - very encouraging sight for those who grow  them from seed.

Pediocactus peeblesianus

Still usually called by it's original name 'Navajoa' this plant rare both in collection and in nature. The plants are restricted to a very specific habitat and been small are very hard to locate. They are usually grafted in culture, but with better understanding of their requirements more and more people reporting success in growing the plants on own roots.

Escobaria vivipara 'kaibabensis'

Escobaria kaibabensis is a smaller form of E.vivipara, a common species found in Arizona, Utah, Nevada and New Mexico. This species does well in culture, blooming reliably in spring or early summer. The picture is taken on the Eastern slopes of Kaibab Plateau.

Echinocactis polycephalus xeranthemoides

Another species from Navajo Bridge area. These plants are easy to see there, a short walk from the parking. It is also much easier in culture than the more widespread ssp. polycephalus, due to it's habitat been within the summer monsoon zone and longer growth period.

Opuntia basilaris 'longiareolata'

This form of wide spread along the deserts of US South-Western Opuntia basilaris grows near Navajo Bridge, southern Arizona. This is one of the plants from the group with unusual light-colored flowers that I found in that area.

Mammillaria grahamii

This is the most common Mammillaria in Arizona. It occurs from California To New Mexico and from Mexican border to Phoenix and a bit more North, abundant in many places.

Echinocereus apachensis

This hybrid 'species' is very common around Apache Trail - a road just West of Phoenix, AZ. The extreme variability of specimens there is overwhelming. The two specimens in my picture are barely giving a hint of plants diversity encountered there.

Coryphantha recurvata

A pretty unusual Coryphantha - large plants, slow but forming multi-headed clumps with age. It is mainly Mexican species, occurring in US only very close to the border, South of Tucson, AZ. A very hansom species.