Cylindropuntia bigelovii

Cylindropuntia bigelovii is a Sonora desert plant. It is a pretty but hostile plant, forming large bushes about 6 ft tall. Dense light yellow spines give the stems that 'Teddy Bear" appearance, but spines are long sharp and barbed. It is best enjoyed from the safe distance.

This picture is taken in Joshua Tree park, an the spot called "Cholla patch". There is a large and dense standing of  Cylindropuntia bigelovii at that spot. Plant is very common down south and east, in southern California and Arizona, and in adjacent Mexico deserts. Plants have pretty flowers that I'll show some day I promise, and also spread vegetatively, dropping stem segments to the ground where they start as another plant. 

This is an easy species in culture, if given lots of warmth and sun. It is hard to recommend it for the collection though, due to size and extreme hostility. 

Mammillaria albicans

Mammillaria albicans is another western Mammillaria with the same recognizable flower characteristics - the long stigma lobes for instance. This group of plants is a good candidate to form a separate genus off the large Mammillaria, some day.

Mammillaria albicans comes from central Baja California and several islands in California gulf. This species blooms in mid-summer, at the time of monsoon rains down at Baja California. It is a beautiful small plant,  wrapped in white cotton. It's flowers produced mostly sporadically, but at least once over a summer my plant will give the full show with 20 or so blooms forming the classic Mammillaria ring.

In culture this is a 'no problem' plant at least once large. Below zero temps better be avoided given the plant's origin. Summer heat and full sun it takes just fine, as you would expect. As everything else I have it in pure mineral substrate, on my weekly summer watering scheduler. 

Echinocereus apachensis

Echinocereus apachensis is a hybrid 'species' growing in Superstition mountains just East of Phoenix AZ. It is a large clumping plant. Plants are very variable, as you would expect from hybrid swarm, and the parents must be Echinocereus engelmannii and Echinocereis fasciculatus, both common in the general area. 

Echinocereus apachensis is best known for it's forms with very long, longer than 4 inches, flexible spines. Not at all every plant look like that. Most wild plants have their central spines shorter, some as short as one inch, some have stiffer and thicker spines. Plants usually have several brown or straw-yellow central spines with other spines white, but some plants are pure white.

Flowers are also remarkable, deep purple-pink in color, relatively large. There is also variation in flower shape, some plants having more E.engelmannii-like bell-shaped flowers, but mostly they are more of a trumpet shape like the one in the picture.

In culture Echinocereus apachensis presents no difficulties. When grown from wild seeds it is a good idea to keep as many plants as possible until they mature, and then select the most remarkable plants to keep in the collection. 

Cereus peruvianus

Here is another plant from Stanford Arizona Garden. It is a tall multi-stemmed Cereus with large white blooms. Flowers open at night and by the time I was there with my camera the blooms were closing. That half-closed flowers sill makes an intriguing shape against the plant ribbed stems.
Cereus perivianus is well known and easy plant, cultivated for over 100 years but better suited for outdoor collection were possible due to it's quick growing rate and size. After reaching the blooming size that is also quite large it is a reliable bloomer.

Mammillaria schwarzii

Mammillaria schwarzii comes from central Mexiacn state Guanajuato from altitudes above 2000m. In culture plants form multi-headed mounds, with small but plentiful white or pale yellow flowers. It is a modest but beautiful plant.

Mammillaria schwarzii is reported in literature as a somewhat difficult plant, a claim that I can not confirm. In my culture it gets no special treatment. Plants do well at full sun, in a cooler location in the greenhouse next to the vent.

Oroya peruviana

The genus Oroya has only two or three species, and comes from Peruvian Andes. They have a distinct hansom appearance and small flowers of unusual shape. Coming from the mountains they can handle light night frost, and do not like heat and full sun coming together. 

In culture Oroyas are slow developing plants, and reaching flowering size in more than 5 years. Larger plants grow quicker and bloom reliably.

Oroya peruviana blooms every summer in my greenhouse, producing it's modes flowers continuously for couple months.

Rebutia fiebrigii

Rebutia fiebrigii is one of many attractive plants from the genus. It is easy and a free-flowering plant, as most of Rebutias. Actually this particular plant in the picture brings in flowers year-around in my greenhouse. In the winter it will be several flowers every other week, in the summer there are flashes of blooms that time by time completely obscure the plant.

Rebutias like lots of sun, but not along with heat. If conditions  are too hot they turn the sun-exposed sides of their stems yellow, recovering in couple days when moved to shady spots. I have to keep my Rebutias in partially shaded side of the greenhouse for the summer mounts here in California.

Rebutias are mountain plants, and not adopted to hot desert summers of low altitude. They come from Argentina Andes. The genus is spread over large rigged area. Habitat like that usually means that the areal is made of relatively isolated spots, and it produces large variety of forms. It is possible to have a collection of several hundreds of plants, all been different Rebutia species and forms, with variety of flower and spines colors and shapes.