Rudgea laurifolia (Humb., Bonpl. & Kunth) Steyerm.
-
Authority
Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
-
Family
Rubiaceae
-
Scientific Name
-
Description
Species Description - Muller-Argoviensis (Mart. Fl. Bras. 6(5): 386, 413. 1881) placed Mapouria sclerocalyx in Mapouria, section E., Rudgeales, in which the flowers are in pedunculate terminal cymes and the stipules are short-connate into a cartilaginous-aculeate bearing truncate sheath, split and lobate at the apex. He compared the species with R. palicoureoides (Mart.) Mull.-Arg., but apparently failed to recognize its more natural placement in the genus Rudgea. This species also would fall into the genus Strempeha of Bremekamp’s treatment, because of the truncate stipules and the umbellately, dichasially ramified primary branches of the inflorescence. In fact, several features which this species shares with the Rudgea fimbriata-cornifolia (Strempelia fimbriata) group are persistent calyx forming a crown over the fruit, pairs of bracts at the forks of the inflorescence, upper portion of style pilosulous, barbate interior of corolla-tube at the base of the filaments, exserted stamens, similar type of calyx, corolla, and hypanthium, the truncate stipules, and the umbellate dichasial branching of the primary axes of the inflorescence referred to. A related species is Rudgea pleurocalyx Standley of Brazil, but that has much larger calyces, hypanthia, and corollas. As Muller-Argoviensis described the fruit inadequately and incorrectly, the following emended description is herewith provided: Bacca ovoideo-oblonga ca 15 mm longa 10-12 mm lata glabra calyce per-sistente truncato 3-4 mm longo 5-6 mm lato coronata, pyrenis duabus complanatis 9-13 mm longis 6-9 mm latis, facie convexa dorsaliter unicarinata acuta longitu-dinali munita, facie ventrali per medium longitudinis depressa. The branches of the inflorescence are found to have a minute puberulence in all the specimens examined of Rudgea sclerocalyx. Although Humboldt, Bonpland and Kunth describe their Coffea laurifolia as having glabrous peduncles, as well as corymbs, the pubescence is actually so minute that it could easily have been overlooked at the time of the description. However, those authors noted the prominent, persistent, truncate calyx crowning the fruit, certainly a conspicuous and diagnostic character of R. sclerocalyx. Although Humboldt, Bonpland and Kunth refer in their description to a longitudinal sulcation along the inner side of the pyrene, this is actually not a fissure, but merely a longitudinal depression.
Distribution and Ecology - Territorio Amazonas, southwestern Venezuela, northwestern Brazil, and adjacent Colombia, in drainage of Rio Negro and Upper Orinoco.
-
Discussion
Coffea laurifolia H. B. K., Nov. Gen. & Sp. 3: 372. 1819, non Salisb. 1796.
Mapouria sclerocalyx Mull.-Arg., Flora 59 : 496-497. 1876.
Psychotria limbata Benth. ex Glaziou, Bull. Soc. Bot. France 56 (Mem. 3d): 351. 1909.
Mapouria spruceana Mull.-Arg., Flora 59 : 496-497. 1876.
Mapouria sclerocalyx var latifolia Mull.-Arg., Flora 59 : 496-497. 1876.
Mapouria sclerocalyx var firma Mull-Arg., Flora 59 : 496-497. 1876.
Mapouria sclerocalyx var coriacea Mull.-Arg., Flora 59 : 496-497. 1876.
Type. Prope Barra, Prov. Rio Negro, Brazil, July 1851, R. Spruce 1723 (lectotype).
I am placing this species in Rudgea by virtue of the presence of closely set, dark, aculeiform, glandular processes on the stipular tract at the apex of the stem at the base of the peduncle and between the base of the uppermost leaves, and because the pyrene has a dorsally carinate ridge down the center and a depressed longitudinal area on the ventral face. Although Muller-Argoviensis described the fruit as ecostate, good fruiting material of this taxon shows the pyrenes with an acutely carinate ridge running down the middle of the dorsal face.