Xerophyte

Central Spines

1(-3), stout, much longer than radial spines, erect, spreading, straw-yellow with dark tip, 2-3 cm long.

Description

Harrisia martiniiSN|8325]]SN|8325]] or Moonlight Cactus is a slender clambering perennial cactus with long much-branched succulent stems 20-50 mm thick, which have five to six longitudinal ribs bearing spines in areoles, each creole with several short flat spines and one to three sharp spines up to 2 m or more metres long. It puts forth many basal shoots, which root where they touch the ground and can form a tangled, impenetrable mass. The large, white funnel-shaped flowers develop in the summer after rain and are up to 20 cm long and very showy. Each flower opens for a single night. Fruit are roughly spherical, spiny, red and 35-50 mm diameter when ripe.

Roots

The root system is fibrous and shallow, with extensive deeper tuberous storage roots developing from the crown in larger plants.

Flowers

Nocturnal, arising singly within areoles near stem tips, white with a pink tinge, funnel-shaped/tubular, to 15-20 cm long; Outer perianth-segments narrow, becoming pinkish, acuminate. Inner perianth-segments broader, short-acuminate, white or tinged with pink. Style green. Pericarpels tuberculate with scales and brown wool.

Blooming Season

Mainly spring and summer. Harrisia martiniiSN|8325]]SN|8325]] has an extraordinary number of blooms which open over a series of days. But even then each individual flower is open only for one evening. Night-bloomers generally open well into the evening, beginning any time after sundown and continuing through the night. Rowers start to fade as soon as the sun comes up, but will remain open and fresh for as long as the sun does not strike them. By mid-morning all from the previous night are spent and the process of developing seed and fruit has begun.

Ribs

Longitudinal 4- or 5(-6)-angled with triangular humps at regular intervals.

Stem

Green to grey-green, fleshy, jointed, 2-2.5(-50) cm in diameter; old stems terete, round in cross section, spineless, young stems vigorous pointed.

Radial Spines

5-7, short, sometimes half as long as the central lying flat.

Fruits

Red, 3.5-4(-5) cm long, not tuberculate or with small conical bumps with red scales surmounted by cushions of hairs and spines (sometimes without spines), and with up to 1000 small black seeds embedded in a sweetish, crisp white pulp; when ripe, split along one side the flowers withering-persistent. The fruits are attractive to birds.

Areoles

With grey, felty hairs.