Xerophyte

Central Spines

1-3 spreading and markedly directed downward, thick, about 20 mm long.

Seeds

Broadly oval.

Roots

Fibrous.

Flowers

Diurnal, wide funnelform, yellow 1,5-2,5 cm long and in diameter (up to 4 cm in the variant known as grandiflora), born on younger areoles from a yellowish woolly crown in summer. Pericarpel and floral tube short scaly. Scales with tufts of dense wool and long reddish bristles. Petals yellow, sepaloids often orange or reddish. Style yellow.

Spines

Variable in size and in colour whitish with reddish tips, changing to grey with age.

Ribs

19-22 low and obtuse and more or less tuberculate.

Stem

Initially globular, but slightly elongated to shortly cylindrical with age, grey-green, 5 to15 cm tall (rarely up to 70 cm tall), 5-10(-20) cm in diameter. Apex densely woolly.

Radial Spines

About 20, shorter, radiating, 7-10 mm long, but sometimes less than 3 mm long.

Fruits

Characteristic, up to 5 cm long, club shaped, balloon-like, pinkish to red, when mature inflated, openings by basal pores. Pericarp initially fleshy but the interior always dry when mature.

Areoles

Approximate, large, conspicuously woolly, with creamy-white to grey-brown felt.