Thelocactus hexaedrophorus

Thelocactos hexaedrophorus is one of those 'classical' plants, well known and still very desired by cactus collectors. This is a slow developing singular plant, with simple grayish stem and large flower. Flowers produced continuously over the summer.

The plant was first described back in 1839, as Echinocactus hexaedrophorus. 

Lobivia haematantha v. jasimanensis

Lobivia haematantha v. jasimanensis WR 792 is one of many nice forms of variable L. haematantha. Plants are small, with noted long back central spine and fleshy roots. Flowers relatively large, and white throat adds color in them.

Ariocarpus agavoides

Smallest of all Ariocarpus, A.agavoides can bloom at only two years old, if grown properly. The small plant stays mostly underground, with thin tubercles protruding above the surface.
Nice pink flowers open in the fall, same as all other Ariocarpus. The distinct feature of this species is that it is the only Ariocarpus that actually has spines.

Coryphantha sulcolanata

Coryphantha sulcolanata is Mexican species, closely related to C.elephantidens but never has pink blooms. Thick round tubercles with plenty of white felt produced at the plant's top make pretty appearance even without flowers. Large silky flowers stay open for two days, like with other coryphanthas.

Notocactus herteri

Notocactus (Parodia) herteri is South American species from Uruguay. It is a larger plant, growing as a ball to a size of 6 inches or more and only after that slowly turning to a column.
Tho plants I have, grown from the same bag of seeds, have much different flower color. The plant at picture has flowers dark pink, and the other produces much lighter pink, almost lavender blooms. Both plants bloom freely and reliably, but only once during the season, in mid-summer.

Weingartia neumanniana

Weingartia neumanniana, is the smaller and slower growing Weingartia, sometimes considered as a difficult to grow plant. The plant has somewhat grayish stem and flowers that are larger than with more common Weingartias, but not that abundant.

This species has thick fleshy roots, the source of problems when not grown in mineral substrate. The common cactus care suits it well, with may be slightly restricted water supply in the summer. Large clumps of this species are rarely seen in culture and always draw a stare.

Matucana paucicostata

Matucana paucicostata is probably the smallest Matucana species. The plants mature ans start blooming at the size of walnut, and generally do not overgrow the mid-sized apple. Large plants usually open flowers in small bouquets of 5-10 blooms at time, forming pretty crown. Looking close at the flower is also a pretty sight, with gentle changing color shades of petals and tight bunch of filaments around style.