Subtribe 4 Echinocactanae

Plants usually low and small, but sometimes several meters tall and then of considerable size, simple or cespitose, terrestrial; stems normally one-jointed but sometimes budding or cespitose or making other joints when injured; ribs few to many, straight or spiral, usually spine-bearing; flowers always solitary at areoles near the apex of the plant, usually from the nascent areoles; fruit more or less scaly or naked, usually dry, in some cases a little fleshy and then somewhat edible, usually dehiscing by a basal pore, but sometimes irregularly breaking apart, or by a circumscissile opening; seeds black or sometimes brown, smooth or papillose.

We recognize 28 genera, most of which are taken from Echinocactus as circumscribed by previous authors.

The subtribe passes into the Echinocereanae on the one hand and into the Coryphantha-nae on the other.

In most of the genera of this subtribe, as well as in a few other genera, such as Oreo-cereus, the seeds escape through a pore at the base of the fruit. If the fruit be gathered before it fully ripens, this pore will not be shown, but, as the fruit ripens, the basal part which is attached to the plant becomes absorbed and disappears and, when the fruit finally falls off, the large opening, sometimes 5 to 7 cm. in diameter, can be seen. In most of the genera the fruit becomes hollow and the seeds are attached on the inner surface until fully ripe, when they fall to the bottom and make their escape. In Homalocephala texensis the fruit bursts irregularly, while in Mila and a few other genera the fruit is a small juicy berr y.

Was this article helpful?

0 0

Post a comment