Monographs Details: Croton hostmannii Miq.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Family:Euphorbiaceae
Scientific Name:Croton hostmannii Miq.
Description:Distribution and Ecology - Distribution. This herbaceous perennial of the savannas, a shrub with spreading branches hardly more than 1 m high, sometimes forming bush islands, seems to be confined to Suriname, British Guiana, and Bolivar and Amazonas, Venezuela. BRITISH GUIANA. Parabaru Savanna, watershed between Rupununi and Kuyuwini Rivers, about 2° 10' N, 15-17 Feb 1938, A. C. Smith 3077 ([male] fl., y. fr. NY); bush island on savanna, Kaieteur Plateau, 7 May 1944, Maguire & Fanshawe 23291 ([male] fl., fr. NY). Parasura Savanna, alt. 600 m, 7 Dec 1952, Guppy 630, F.D. 7645 ([male][female] fl., y. fr. NY); occasional in open savanna, vic. Hariwa Quarry, 32 mi. S of Mackenzie, 18 Jan 1955, Cejwan 39275 ([male][female] y. fl. NY) ; upper Mazaruni River, 60° 10' W , 22 Sep-6 Oct 1922, De La Cruz 2109, 2220 ([male][female] fl. N Y ) ; occasional in Kamana Savanna, en route to Kopinang Falls, southern Pakaraima Mountains, 28 Aug 1961, Maguire, Maguire & Wilson-Browne 45971A ([male][female] fl. NY). VENEZUELA. Bolivar: Savanna pasture surrounded by forest, Arabu, alt. 1400 m, Mt. Roraima, 1927, Tate 271 ([male][female] fl. N Y ); Urkara Falls, Rio Caroni, alt. 480 m, 6 Oct 1946, Cardona 1740 ([male] fl. NY). Amazonas: Locally abundant on open laja, 8 km below Raudal Galineta, alt. 130-300 m, Rio Siapa, Jul 1959, Wurdack & Adderley 43507 ([male][female] fl., fr. NY).

Discussion:Miquel quotes this species only from Suriname, and Lanjouw, who has seen Miquel's original, considers it to be endemic there. However, I have not seen a single specimen from Suriname; neither has Lanjouw with the exception of Miquel's type. According to Miill. Argoviensis, C. hostmanni should have all 5 sepals of equal size, which is not the case with any specimen examined by me. They all show two large and three small ones, or one large and four small sepals. He also describes the leaf tip as being obtuse or even emarginate, which agrees with the photograph of the type. But because of a high variability of the leaf shape, this distinction can hardly be considered critical. Croizat thinks "a rufus cast on innovations and youngest leaves distinguishes this species from its allies" (meaning probably C. subincanus).
Distribution:Guyana South America| Venezuela South America|