Cereus uruguayanus
Darwiniana 24(1–4): 448 (1982). Remarks: Kiesling ascribed C. uruguayanus to Ritter and referred to "Piptanthocereus uruguayanus Ritter," an invalidly published name. Since Ritter's epithet is in a different genus, Kiesling's ascription to Ritter is an error.
Family
Cactaceae
Genus
Species
Cereus uruguayanus
Author
R.Kiesling
Chinese genus
天轮柱属
Chinese name
-
DescriptionEdit description
Habit
It is a perennial treelike cactus that grows like a candelabrum with numerous columnar branches, 5-10(-15) m high with distinct trunks.
Description
Cereus hildmannianusSN|6489]]SN|6489]] subs. uruguayanus (R.Kiesling) N.P.Taylor is a geographical or morphological form of the widespread Cereus hildmannianusSN|6489]]SN|6489]] that occurs only in Uruguay. Its stems usually bears long golden or brown spines while the standard hildmannianus is almost always free of spines. Apart from the difference in spines they are almost identical and not readily distinguishable if not for the geographical provenace. It produces numerous showy white flowers 10-15 cm across that are followed by goose-egg-size succulent fruits containing a delicately sweet white pulp with delightfully crunchy black seeds
Flowers
Very large, nocturnal, elongated, funnelform, 20 to 30 cm long. Tube somewhat scaly, greenish brown without areoles and spines. Outer perianth-segments reddish brown, inner perianth-segments white, broad and obtuse. Ovary naked, 2.5 to 3 cm long. Stamens white, anthers yellow. Stigma lobes approx 15 clear yellow.
Blooming Season
It blooms at night in spring through summer. The buds grow quickly, shooting out from the branches like so many small snakes. Within two weeks, dozens of flowers open, always at night and all or nearly all flowers open simultaneously at the same time. By midmorning the following day, all had closed and drooped. This is apparently a water-saving strategy by cacti. The plant usually buds and flowers about two weeks following any warm-season rain. The fruits usually ripen within a month. Buds may erupt well into fall, even early winter, if sufficient temperatures and rains fall. During dry times, the buds often fall off prior to opening.
Spines
Usually present, acicular golden-yellow to brown, six radial, rigid from 5-10 mm lomg, and only one longer (to 5 cm long) central spine and very pointed. Areoles at the top of the plant often have an increased number of spines, which are longer and with more wooll.
Ribs
(4-)5-6(-8), thin to obtuse, slightly indented, 2.5-3.5 cm high, rounded, green often with large yellow patches along the sides.
Stem
Cylindrical, segmented, bluegreen to dull green, often glaucous when young, to 15 cm in diameter.
Fruits
Pear-shaped, red with white pulp. The Peruvian apple cactus may produce fruit 3-4 years after propagation from seed.
Areoles
Distant, brown, large 2 cm apart.