Xerophyte

Habit

Solitary rosette-forming, geophytic cactus rising slightly above ground level.

Description

Ariocarpus trigonusSN|2078]]SN|2094]] is one of the largest species that distinguishes for the long leaf-like triangular tubercles and peculiar yellow flowers. It is quite variable in tubercle shape and size and has received numerous unnecessary names of no botanical value, representing no more than local phenotypes

Roots

Tap root.

Tubercles

Upright yellow/brownish grey, divergent, not closely set or basally compressed, acute at the apices, flattened and smooth adaxially, not fissured, strongly incurved, 3-8cm long, 1-2.5cm broad, usually twice as long as wide, but variable from long and thin to short and broad.

Flowers

Cream-white to yellowish-white or yellow (occasionally with reddish mid-ribs) with a satin sheen, 3 to 5 cm in diameter up to 4 cm long.

Blooming Season

They come in late autumn or early winter.

Stem

5 to 30 cm in diameter, 4 to 25 cm tall, globose, more or less depressed, rounded on top, mostly yellowish-green.

Fruits

Whitish or greenish, 7-20 mm long, 5-10 mm across.

Areoles

Ariocarpus trigonusSN|2079]]SN|2094]] bears only small basal areoles, whose meristem do not divide, monomorphic. On the contrary Ariocarpus retususSN|2094]]SN|2079]] has floral and spinous parts separate, dimorphic. However spine-bearing portions of the areoles are present at the tips of the tubercles of tubercles only in very small specimens.