Cactus intortus Mill.

• Title

  Cactus intortus Mill.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Cactus intortus Mill.

• Description

  Flora Borinqueña Cactus intortus Melon de costa Turk's cap Family Cactaceae Cactus Family Cactus intortus Miller, Gardener's Dictionary, edition 8, no. 2. 1768. Melocactus astrosanguineus Pfeiffer, Enumeratic Diagnostica Cactearum 44. 1837. Melocactus portoricensis Suringar, Verslagen der Koninklijke Akademie van Wetenschappen III. 9: 408. 1891. A fleshy, leafless, spiny plant of very unusual form and aspect, called also Melon Cactus and Turk's-head, growing naturally only in dry regions, and, for the most part, near the sea, but not restricted to within saline influence. In Porto Rico it grows at low elevations, in rocky or sometimes in sandy soil, in the dry, southwestern districts; we have observed it from the vicinity of Guanica westward to the Mona Passage, where it ranges north to Punta Melones, and gave that point its name. An isolated station, and the one farthest from the coast, has been recorded at El Fuerte, on the Coamo River, below Coamo, but we failed to find any there in 1922; we found another isolated station at Cape San Juan in 1930; it inahbits the small island Vieques, the Virgin Islands, the Bahamas, and the Lesser Antilles from St. Martin to Antigua. The plants are often grown as objects of interest, but do not long endure moist or wet climates. Cactus (a Greek name for thistle) is a genus established by Linnaeus, who included in it all plants of the Cactus Family known to him in 1753; by recent authors the generic name has been restricted to about 20 species of globose or short-cylindric, ribbed plants, with the flowering areoles characteristically confluent into a terminal, densely woolly and bristly mass (cephalium). The small flowers have a nearly cylindric tube and a several-lobed limb; there are several, or many stamens, with very slender filaments; the smooth ovary contains many obvules, the style is slender, the stigma several-rayed. The fruit is a small, smooth, obconic, or obovoid berry, which projects beyond the cephalium, topped by the withering-persistent corolla. Cactus intortus is depressed-globose when young, becoming ovoid and from 0.3 to 0.7 meter high, and up to about 0.3 meter in diameter when old; it is dull green, with from 14 to 25 wavy-topped ribs from 2 to 4 centimeters high, the areoles bearing a cluster of stout, stiff, yellow to brown spines, from 1.5 to 5 centimeters long. The cephalium is, at first, nearly flat, at length cylindric, becoming about 0.3 meter high or less and from 8 to 10 centimeters in diameter, densely white-woolly and brown-bristly; the pink, or rose flowers are from 10 to 15 millimeters long, the inner segments pointed. The red or rose berry is from 20 to 25 millimeters long, the small dull black seeds tubercled. Another species, Cactus Antonii Britton with more slender spines up to 7 centimeters in length, inhabits the small islands Mona and Desecheo in the Mona Passage.