shaferi is a clustering species with many basal and
lateral offshoots and huge yellow flower. It is very spiny and produces
large pale yellow flowers.
Stems: Dark green to greys-green globular, becoming cylindric
reaching a height 5-15 cm and a diameter of 2 - 4 cm or more.
Ribs: About 10 very low, laterally compressed.
Areoles: Closely set often brown on young plants.
Radial spines: 6 to 15 about 1-1,5 cm long, rigid, acicular,
pointing outward white to brown.
Central spines: Several (usually 4), thicker, sometimes flat, about 3 cm
long, and brown to black with yellow tips, one often stouter than the
Flowers: 4-6 (or more) cm long. They are pale-yellow to bright
lemon-yellow. Buds are very hairy covered by long silky hairs and grow
laterally from the centre of the stem. The tube is slightly curved,
funnel-shaped, slender and a greenish white, with liner to ovate-linear
scales often red at the base, with white and black down. Style greenish
white, stigma cream coloured (rarely greenish).
Blooming season: Blooms in flushes in late spring and
occasionally in summer. The flower lasts one or two days only.
Fruit: Orangish, dehishent with white pulp.
Seeds: Black, rugose, about 1,5 mm in diameter.