Xerophyte

Habit

Plants erect that will form clumps with some branching with age, 30-100 cm high and 1-3 metres in diameter, but usually couldn’t get very tall as segment kept falling apart.

Description

Tephrocactus aoracanthusSN|8453]]SN|8453]] is one of the most hazardous species with fierce, wonderful spines. The spines are very stiff and stick out to every thing that enter in contact with them, this way the stems segment spread around in the environment.

Stem Segments

Somewhat fragile (easily detached), ellipsoidal to ovoid, prominently tuberculate, 5-10 cm long and 4-8 cm in diameter, of a very characteristic pale grey or greys-green colour.

Tubercles

Moderately to strongly defined, forming a network of more or less regular spiralling lozenge in the epidermis.

Flowers

Large, white to light pink, 4-6 cm long by 5-8 cm in diameter; tepals broadly spatulate with a hard and brown mucro; pericarpels inverted cone-shaped up to 3 cm long and 2 cm in diameter, with many glochids and sometimes with spines up to 15 mm long on rims at the top of the pericarpel. The stamens are sensitive; filaments white; anthers yellow; style clavate white with up to 8 stigma lobes.

Spines

7-8, stout, very unequal, erect or spreading in all directions, slightly flexible to somewhat rigid, often twisted and intertwined, reddish brown to black, round or slightly angled in cross section, up to 1-10(-15) cm long. (in var. paediophilus the spines are as much as 30 cm long, papery but still very sharp)

Fruits

Spherical to oval, up to 3 cm in diameter dehiscing irregularly, sometimes with persistent spines.

Areoles

Small on top of a conical protuberance, as many as 60 per segment (but usually about 30) extending to the base. The basal areoles are spineless 2-3 mm in diameter, while the areolae in the upper two thirds of the segments are significantly larger (up to 6mm) and bear spines. The new areoles at first are filled with white hyaline wool (rarely brown at the the centre). In the centre of the areola there are stiff, yellowish brown glochids up to 5 mm long.