Disocactus crenatus, commonly known as the crenate orchid cactus, is a species of cactus cultivated for its large flowers. It is a critical parent plant in creating epiphyllum hybrids commonly cultivated worldwide.
Description
The stem is erect to ascending, and profusely branched. The primary stems are terete (tapering at both ends) and 3-angled for a short portion at the base, becoming ligneous (woody) and flat for most of their length. The secondary stems are flat, with flattened portions being 60-centimetre long (24 in), 6–10-centimetre wide (2.4–3.9 in), and stiff and rather succulent. The phylloclades are lanceolate to long linear, acute or obtuse, median nerve rather thick, margins deeply or coarsely crenate, lobes oblique; areoles at the bases of stems sometimes bearing hairs or small bristles, internodes (plant stem part between nodes) narrow or broad. The epidermis is green or gray-green and smooth.
The flowers are up to 18–29-centimetre long (7.1–11.4 in) and 15–20-centimetre wide (5.9–7.9 in). The species is nocturnal but may remain open for several days, becoming quite fragrant. The outer tepals are inserted within 2 cm of the receptacle apex, 10–12 cm long, broadly oblanceolate to linear, greenish yellow to tawny yellow or reddish amber. The outermost tepals are sometimes margined in red or streaked. The inner tepals are as long as outer tepals, spathulate to oblanceolate, acuminate to mucronate, white, creamy white, or greenish yellow. The Pericarpel (hypanthium) is 5-angled, 3 cm long, 1.5-1.7 cm thick, with acute, long-decurrent podaria, bracteoles (small bracts) subtening (2–8) spines up to 7 mm long, and green in color. The receptacle is 10–12 cm long, about 1.5 cm thick at its middle, and green (or often reddish) at the apex, or reddish throughout. It bears numerous linear to oblong keeled bracteoles. The bracleoles are 2–3 cm long and appear in a spread formation....
