Origin and Habitat: Northeast of Aquidauana (Serro de Maracaju) and Cipolandia, Mato Grosso, Brazil
Altitude range: Approximately 230 metres above sea level.
Habitat: Discocactus pachytheleSN|12051]]SN|12051]] grows on rocky clearing in the greater catinga.

• Discocactus pachythele Buining & Bredero

• Discocactus heptacanthus (Barb.Rodr.) Britton & Rose
• Malacocarpus heptacanthus Barb.Rodr.
• Neodiscocactus heptacanthus (Barb.Rodr.) Y.Itô
• Discocactus boliviensis Backeb.
• Neodiscocactus boliviensis (Backeb.) Y.Itô
• Discocactus cangaensis Diers & Esteves
• Discocactus cephaliaciculosus Buining & Bredero ex P.J.Braun & Esteves
• Discocactus cephaliaciculosus subs. nudicephalus P.J.Braun & Esteves
• Discocactus crassispinus P.J.Braun & Esteves
• Discocactus crassispinus subs. araguaiensis P.J.Braun & Esteves
• Discocactus diersianus Esteves
• Discocactus estevesii Diers & Esteves
• Discocactus flavispinus Buining & Bredero
• Discocactus goianus Diers & Esteves
• Discocactus diersianus subs. goianus (Diers & Esteves) P.J.Braun & Esteves
• Discocactus diersianus var. goianus (Diers & Esteves) P.J.Braun & Esteves
• Discocactus griseus Buining & Bredero
• Discocactus catingicola var. griseus P.J.Braun & Esteves
• Discocactus hartmannii (K.Schum.) Britton & Rose
• Echinocactus hartmannii K.Schum.
• Neodiscocactus hartmannii (K.Schum.) Y.Itô
• Discocactus hartmannii subs. giganteus P.J.Braun & Esteves
• Discocactus hartmannii subs. setosiflorus P.J.Braun & Esteves
• Discocactus heptacanthus subs. melanochlorus (Buining & Bredero) P.J.Braun & Esteves
• Discocactus melanochlorus Buining & Bredero
• Discocactus heptacanthus var. riomortensis P.J.Braun & Esteves
• Discocactus heptacanthus var. semicampaniflorus (Buining & Bredero) P.J.Braun & Esteves
• Discocactus semicampaniflorus Buining & Bredero
• Discocactus lindaianus Diers & Esteves
• Discocactus magnimammus subs. bonitoensis Buining ex J.Theun.
• Discocactus hartmannii var. bonitoensis (Buining & Bredero) P.J.Braun
• Discocactus mamillosus Buining & Bredero
• Discocactus hartmannii var. mamillosus (Buining & Bredero) P.J.Braun
• Discocactus nigrisaetosus Buining & Bredero
• Discocactus catingicola var. nigrisaetosus (Buining & Bredero) P.J.Braun & Esteves
• Discocactus pachythele Buining & Bredero
• Discocactus paranaensis Backeb.
• Discocactus patulifolius Buining & Bredero
• Discocactus hartmannii subs. patulifolius (Buining & Bredero) P.J.Braun & Esteves
• Discocactus hartmannii var. patulifolius (Buining & Bredero) P.J.Braun
• Discocactus piauiensis P.J.Braun & Esteves
• Discocactus prominentigibbus Diers & Esteves
• Discocactus rapirhizus Buining & Bredero
• Discocactus catingicola subs. rapirhizus (Buining & Bredero) P.J.Braun & Esteves
• Discocactus silicicola Buining & Bredero
• Discocactus silvaticus Buining & Bredero
• Discocactus spinosior Buining & Bredero
• Discocactus squamibaccatus Buining & Bredero
• Discocactus squamibaccatus var. longiflorus P.J.Braun & Esteves
• Discocactus subterraneo-prolifer Diers & Esteves

• Discocactus heptacanthus subs. catingicola (Buining & Bredero) N.P.Taylor & Zappi
• Discocactus catingicola Buining & Bredero

• Discocactus heptacanthus subs. magnimammus (Buining & Bredero) N.P.Taylor & Zappi
• Discocactus hartmannii subs. magnimammus (Buining & Bredero) P.J.Braun & Esteves
• Discocactus hartmannii var. magnimammus (Buining & Bredero) P.J.Braun
• Discocactus magnimammus Buining & Bredero

Description: Discocactus pachytheleSN|12017]]SN|12051]] is a controversial species seemingly intermediate between Discocactus heptacanthusSN|12051]]SN|12017]] ssp. heptacanthus and Discocactus heptacanthusSN|12017]]SN|12017]] ssp. magnimammus. It is a small a solitary flattened cactus that form a white to light brown cephalium at maturity and blooms on warm summer nights. The names Discocactus pachytheleSN|12017]]SN|12051]] is not accepted by many botanists that treat it as synonym of Discocactus heptacanthusSN|12051]]SN|12017]], but it still has a value for a collector because they identify plants with particular characters.
Stem: Flattened-spherical, up to 14-22 cm in diameter and 7-9 cm in height (without cephalum), dark green.
Ribs: 13-16, nearly vertical.
Areoles: Woolly, almost round. Number of areoles per rib is about 5-7 on plants with cephalium.
Spines: Quite powerful, somewhat bent towards the plant's body, bright yellowish-brown to grey with a dark tip, and somewhat thickened at the base.
Radial spines; 5(-7), the lower one up to 45 mm in length curved down, the other sideward pointing, 10-32 mm long, the upper ones the shorter.
Cephalia: 50-60 mm in diameter, about 30 mm in height, with bright grey brown hairs and several fine, needle-like spines, particularly along the edge.
Central spines: None.
Flowers: 95-110 mm long, 70 mm wide, white. The position of the stigma is at the top of the stamens.
Fruits: White.

Bibliography: Major references and further lectures
1) Buining, A.F.H. "Die Gattung Discocactus Preiffer." Venlo, O.J. 1980 page page 208
2) Cac.& Succ.Journal USA 1975.
3) Braun P. Kakteenkartei K.u.a.S. 40 (8) page 22 1989.

Cultivation and Propagation: Discocactus pachytheleSN|12051]]SN|12051]] is not the easiest plant to keep happy, so it isn't a plants for beginners, in fact collectors consider the discocacti to be rarities which requires skilful cultivation. Under glass, it isn't difficult, but appreciates milder winter temperatures and more generous summer watering than most of the other genera of compact cacti. When grown to maturity, however, it possess an exotic look shared by no other cacti, and it generally attract a lot of attention.
Growing rate: It is slow growing.
Soil: It likes very porous standard cactus mix soil. Prefer a low pH compost, avoid substrata rich in limestone; otherwise growth will stop altogether.
Repotting: They generally resent being repotted and can take a long time to establish.
Fertilization: Feed with a high potassium fertilizer in summer.
Exposition: The plant tolerates bright situations but enjoys filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Tends to bronze in strong light, which encourages flowering and heavy spine production.
Waterings: Discocacti are very rot prone when kept on their own roots and though they can’t endure long stretches of total dryness, too much water with cool will rot them, as their weak root systems tend to be inefficient at sucking up water from wet soil.
Hardiness: It is rather difficult to grow and frost tender, it can’t stand cold, or even fairly cool temperatures and should be kept at above 15° C if grown on its own roots (8°C if grafted).
Pests & diseases: It may be attractive to a variety of pests or diseases:
- Red spiders: Red spiders may be effectively rubbed up by watering the plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new growth among the wool with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales: Scales are rarely a problem.
- Rot: Rot it is only a minor problem with cacti if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Seeds or grafting. Seeds germinate in 7-14 days at 21-27° C in spring, remove gradually the glass cover as soon the plants will be well rooted (ca 1-2 weeks) and keep ventilated, no full sun for young plants! .Young seedlings are often grafted on a low stock to keep the plant in a good shape.