Ferocactus glaucescens

O Ferocactus glaucescens, cacto-bola ou cacto-azul, é um cacto com a forma de um barril, natural das montanhas de calcário do estado de Hidalgo no México.

Herbácea e suculenta de sol pleno. Pode atingir até 40 cm de altura e floresce no Inverno. 

Prefere clima quente e seco e por seu pequeno porte, fica muito bem em vasos com forração de pedriscos, ou em canteiros em terreno rochoso. 

As regas devem ser de cerca de uma vez por semana, já que a planta não tolera muita água. O solo deve ser bem drenado e arenoso.

Description: Solitary or basally suckering, barrel cactus. Multiple heads are produced as the plant ages and can form a very large mound.

Stems: Glaucous grey, up to 55 cm in height, 50 cm in diameter. Globular depressed at the apex, it becomes shortly columnar as it ages. 

Ribs: 11 to 15 

Radial spines: 6 or 7, 2.5-4 cm long, straight, light yellow.

Central spines: 0 or 1, very similar to the radials.

Flowers: Lemon yellow, funnel-shaped, 3-4 cm in diameter. The tepals are oblong, lanceolate, silky, shining; the margins are finely fringed. Stamen, style and stigma are yellow. Stigma lobes: 12-15.

Blooming season: Late spring and summer. The flowers last a very long time. The plants start flowering when about 13 cm in diameter.

Fruit: White, 2 cm long with the remnants of the flowers attached.

Cultivation: Plants are slow growing to start, but are easy to grow and require little care once they have reached a nice flowering size. 

F. glaucescens is suited for any rich, well drained soil in full sun, through-out the year. Pot culture: It grows best in a fairly roomy, well-drained container filled with a porous cactus soil mixture that doesn't contain too much humus.

To insure robust plants, water and fertilize during the aestival growth cycle. This plant needs plenty of water (indicatively, about once a week).

It’s necessary to avoid wetting the bodies of these plants while they are in sunlight. A wet cactus in the sun light can cause sun burning which can lead to scars, or even fungal infections and death.

In winter, keep completely dry at 10°C. This usually aids in maintaining a healthier plant, but it can tolerate sporadic light frost. 

Habitat: This species is found within the numerous limestone hills and boulders at several locations in the state of Hidalgo, Mexico. 

It has been noted to favor the more northern slopes, and the plants are well associated with the rocky, juniper woodland community, up to around 1200 m in elevation.

Common Name: Blue Barrel Cactus

Reproduction: Seeds are the typical way of reproducing. These cacti will easily grow from seeds and some from cuttings. Seeds can be sown in the spring or summer in well-drained pots of soil for cacti.

Sow the seeds thinly on top. Cover them with a bit of fine quartz grit. Moisten and lay a piece of glass across the top. The pots should be set in a warm greenhouse until they start to sprout, after which the glass should be progressively removed so they can receive full light and air.

It isn't good to keep the glass over the seedlings. The well developed seedlings can be planted separately in small pots. 

Cuttings made from pieces of the stem of any size can be detached and laid aside for a few days to allow a protective "skin" to form over the cut. 

They can then be planted in pots. Place them in a spot where they will receive sun, and do not water until the soil becomes fairly dry. After a while the soil can be moistened regularly, but never kept constantly saturated.