Monographs Details: Chelonanthus fruticosus Maguire & B.M.Boom
Authority: Maguire, Bassett. 1989. The Botany of the Guayana Highland- Part XIII. Mem. New York Bot. Gard. XIII: 1-127.
Family:Gentianaceae
Description:Species Description - See discussion

Distribution and Ecology - Suflfmtescent plants of low altitude savannas, Vaupes-Guainia areas of Colombia and Venezuela. VENEZUELA, territorio amazonas: 1854, Spruce 3551 (holotype K, isotype NY); arching shmb with greenish-white flowers, occasional on white sand, scrub savanna, Yavita, Rio Atabapo, 19 Oct 1950, Maguire 29315 (NY); shmb 0.5-1.5 m, flowers green, frequent, Pimichin-Yavita Rd. nr. Pimichin, 130-140 m, 14 Apr 1953, Maguire & Maguire 35601 (NY); suflrutescent to 1 m tall, flowers pale green, frequent, Yavita-Pimichin trail nr. Yavita, 10 Jun 1959, Wurdack & Adderiey 42901 (NY); Wurdack & Adderiey 43722 (NY).

Discussion:

Type. Ad flum. Guainia v. Rio Negro supra ostium fluminensis Casiquiare (Amazonas, Venezuela), 1854, R. Spruce 3551 (holotype K, isotype N Y ).

Lisianthus (sect. Adenolisianthus) arboreus Spmce ex Progel, n. bras. 6(1): 240. 1865.

Adenolisianthus arboreus (Spmce ex Progel) Gilg, Nat. Pflanzenfam. 4(2): 98. 1895.

Irlbachia alata (Aublet) Maas subsp. arborea (Spmce ex Progel) Persoon & Maas, Proc. Kon. Ned. Akad. Wetensch. Ser. C. 88(4): 410. 1985

Progel (1865) established the section Adenolisianthus in Lisianthus with two species, L. arboreus Spmce ex Progel and L. virgatus Progel, on the basis ofa glandular gynobase. Gilg (1895) elevated the sectional name to generic status, providing distinction from Chelonanthus by minute pollen exine diflferences. The specimens before us exhibit neither of these diflferences. They do exhibit a shrubby tendency-a quality which perhaps led to Spruce's epithet arboreus. This epithet, however, cannot be retained when transferred to Chelonanthus because it would thus be a homonym (C arboreus Britton, =Rogersonanthus arboreus (Britton) Maguire & Boom). Therefore, a new name is here selected. The pollen of Chelonanthus fruticosus, however, also is distinctive in not exhibiting the abundant globular processes so conspicous in the other species of the genus admitted here. The shmbby habit and pollen distinction may well argue that this species is misplaced in Chelonanthus. The inflorescence, contrarily, argues that the species is properly placed.

Specimens examined. COLOMBIA, vaupes: 4-5 ft, flowers green-yellow, Mt. Chiribiquete, quartzite base, summit about 800-1200 ft, above forest floor, 1700- 2100 ft above sea level, Macaye River, 24 Jul 1943, Schultes 5614 (GH, NY); same locality, Schultes 5441 (GH, unicate).

Besides the isotype, Spruce 3551, there are five additional collections of this well-marked species at N Y , cited above, all of the Yavita-Pimichin area on the divide between the Atabapo and Guainia drainages. The species is evidently thus restricted geographically, and is clearly marked. It a satisfaction to have these new collections of this taxon, which previously had been known only from the type.