Disocactus crenatus

The stem is erect to ascending, profusely branched, primary stems terete (tapering at both ends) or 3-angled for a short portion at base, becoming ligneous (woody), flat at most of their length, secondary stems flat, flattened portions to 60 cm long, to 6–10 cm wide, stiff and rather succulent. The leaves 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 almost grayish green, smooth.

The flowers are up to 18–29 cm long and (10-)15–20 cm wide, nocturnal, but remaining open for several days, fragrant. The outer tepals are inserted within 2 cm of receptacle apex, (7-)10–12 cm long, broadly oblanceolate-linear, greenish yellow to tawny yellow or reddish amber, the outermost sometimes margined red or streaked; inner tepals as long as outer, 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 0-2 (-8) spines to 7 mm long, green. The receptacle is 10–12 cm long, about 1,5 cm thick at middle, green often reddish at apex or reddish throughout, bearing numerous linear to oblong, obtuse, ± keeled bracleoles 2–3 cm long, ± spreading. The nectaries are about 3–4 cm long, stamens numerous, declinate,[2] shorter than the tepals, inserted in two zones the lower one ca 4 cm long, from a point ca 4 cm from the ovary chamber, the upper zone forming a throat circle ca 2 cm above, filaments 5–7 cm long, pale yellow or pale greenish yellow; style 15–20 cm long, as long or longer than stamens, 2–3 mm thick, widest at base. The stigma lobes are white, 8-9, papillose (nipple-like). The fruit is oblong to globose (globe-shaped), the podaria long decurrent, acute.

This subspecies differs from the typical variety by: stems 4–6 cm wide, lobes usually semicircular; pericarpel and receptacle subterete (tapering at the bottom) in cross-section; pericarpel with subconical (somewhat cone shaped at the bottom) or obtuse, shortly decurrent podaria and with bracteoles subtending ca 6 (0-20) spines to 12 mm long; outer tepals usually inserted within 4–8 cm of tube apex; fruit globose, the podaria shortly decurrent, obtuse.