Xerophyte

Leaves

Minute, that (like in all Pterocactus) fall away early.

Seeds

Typical of the genus, winged, with a strongly flattened aril; uneven on its periphery.

Roots

Strong, napiform, very long, cream-coloured.

Note

Like trees that lose their leaves in autumn, the pterocati lose annually their aerial parts (segments) in a controlled way using a layer of bark to seal the subterranean, living root-stock or keep their branches alive until harsh conditions kill them. Then the grower throws the plants out, not realizing that the root is still healthy. The best thing to do when pterocati begin to dye back is to stop watering them, and let them stay dry and dormant. A few months later they will send up a shoot on their own. When that shoot appears, resume watering.

Flowers

Diurnal, yellow, yellow-copper, brownish or dull purple, with a red stigma up to 2,5 cm in diameter, growing apically at the tip of new stems. Without a clear floral tube, distinguishable and almost continuous with the stem.

Blooming Season

Summer.

Stem

Thin, cylindrical, more or less tuberculate (tubercles as broad as they are long, arranged in spirals), segment unbranched usually arising from the root-stock (or rarely joined), they are green to brown, up to 15 cm long (but usually less than 10 cm long) and 1-1,5 cm in diameter.

Fruits

Dry, 2-2,5cm in diameter, strongly tuberculate, dehiscing transversally in the upper part, opening up like a cap and setting the seed free.

Areoles

Somewhat woolly, with many yellowish glochids, 2-4 mm long.