Xerophyte

Central Spines

1, straight, porrect, with light tip. Similar in shape and colour to lower radials.

Seeds

Reniform 2-2,5 mm long, 1,5 mm wide.

Description

Coriphantha poselgeriana is a heavily spined, imposing species, and reminds one of an Echinocactus. The nomenclature of this variable taxon is quite confusing. Coriphantha poselgeriana has two forms, often referred to as distinct varieties or subspecies. The forms from North of the Sierra de Paila are more strongly spined (Coryphantha poselgerianaSN|10365]]SN|10245]] var. valida) than the ones to the South, which have more radials (Coryphantha poselgeriana var. saltillensisSN|10245]]SN|10365]]). But the transition is continuous, and separation of a subspecies is questionable.

Roots

Thin taproot.

Tubercles

Up to 2(-3) cm long and 5 cm wide, convex, conical, 4-6 edged with a deep wooly groove, near the areole, rounded near the end. Parastichy number 8-13. With yellow-orange glands over the whole length. Axil woolly with glands.

Flowers

6-7 cm, varying from whitish-rose with a pink centre, to carmine red, and in San Luis Potosí even yellow-flowering forms occur.

Stem

Globular to short cylindrical, solitary or slowly clumping, reaching up to 30 cm in height and 18 cm in width. Dull bluish green, apex rounded and woolly.

Radial Spines

5 to 12, with 7-8 of them radiating sideways and downwards, straight or recurved, strong, subulate, the 3-4 lower ones are somewhat fattened, up to 30-40 mm long. Whitish, later reddish or blackish, with a darker tip and ultimately greysh.

Fruits

Green, juicy, with persisting flower remnants. 25-50mm long, 7-18 in diameter.

Areoles

About 7 mm wide, round with short wool.