Monographs Details: Declieuxia tenuiflora (Willd. ex Roem. & Schult.) Steyerm. & J.H.Kirkbr.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Description:Distribution and Ecology - Distribution. Venezuela and Brazil. VENEZUELA. Bolívar: on boulder at edge of slope forest, Cerro Altamira, alt 425 m, 21 Oct 1953, Maguire, Wurdack & Bunting 35912. Amazonas: igneous knob along Cano Asisa, 3 km below Paru savanna camp, Río Ventuari, alt 200 m, 17 Feb 1951, Cowan & Wurdack 31539; southern part of Isla del Raton, 5° 2' N, 67° 46' W, alt 90 m, 22 Nov 1965, Breteler 4787; near Danta (Tapir) Falls, Río Cuao, Río Orinoco, alt 125 m, 19 Nov 1948, Maguire & Politi 27337; Laja Catipan, Río Yatua, alt 100-140 m, 26 Sep 1957, Maguire, Wurdack & C. K. Maguire 41580; Caño San Miguel between Limoncito and Caño Ikebenie, about 70 km from mouth, alt 100-140 m, 29 Jun 1959, Wurdack & Adderley 43239. BRAZIL. Terr. Rio Branco: wet sand pockets along southeast escarpment, Serra Tepequem, alt 1000-1200 m, 29 Nov 1954, Bassett & C. K. Maguire 40084. Distrito Federal: Cabo Frio, arenosis maritimis, 1835, Riedel s n; Praia de Sernambetiba (Recreio dos Bandeirantes), 23° 00' 13" S, 43° 20' 49" W, near sea level, 4 Apr 1952, L. B. Smith et al 6408.

Discussion:

Tournefortia tenuiflora Willd. ex Roem. & Schult., Syst. 4: 540. 1819.

Knoxia brasiliensis Spreng., Syst. 1: 406. 1825.

Declieuxia brasiliensis (Spreng.) Muell.-Arg., Flora 59: 434. 1876.

Declieuxia herbacea Ch. & Schl., Linnaea 4: 11. 1829.

Type. Cumana [Estado Sucre], Venezuela, Humboldt.

Willdenow described Tournefortia tenuiflora from a plant collected by Humboldt, presumably, according to the data, from Cumana in eastern coastal Venezuela. An examination of the photograph of the type from B leaves no doubt that it is the same taxon known as Declieuxia brasiliensis (Spreng.) Muell.-Arg., basionym Knoxia brasiliensis Spreng., based on a Sello collection from the vicinity of Rio de Janeiro, Brazil. The same plant was also described by Chamisso & Schlechtendal as Declieuxia herbacea.

An examination of the material at hand reveals a surprising match and exactitude between specimens recently collected in Venezuela and those collected from the vicinity of Rio de Janeiro. Ordinarily, differences amounting to specific or subspecific categories are usually encountered among such widely geographically separated plants. In the present instance, however, no such differences are forthcoming.

Although the original descriptions of Knoxia brasiliensis and Declieuxia herbacea state that the stems and leaves are glabrous, study of topotype material from Rio de Janeiro indicates variation from completely glabrous stems and leaves to those moderately puberulous. The Venezuelan specimens likewise vary in this respect, and some of them from Territorio Federal Amazonas have larger leaf blades and more elongated stipules, as well as considerable pubescence on the stems and leaves, as contrasted with some Brazilian collections or those from Estado Bolívar, Venezuela, but, again, there is no correlation in these characters. The Maguire & Maguire 40084 collection from Terr. Rio Branco, Brazil, matches remarkably well the smaller-leaved collections made by Smith et al 6408 and by Riedel s n from the Rio de Janeiro region, while the Maguire, Wurdack & Maguire 41580 collection from Río Yatua, Amazonas, Venezuela, even more distant from the region of Rio de Janeiro than the Terr. Rio Branco, likewise, is more or less identical with the collections from Rio de Janeiro.

Although there are no known Venezuelan specimens at present from the type locality of Cumaná, the collection of Maguire, Wurdack & Bunting 35912 from Cerro Altamira (east of Cerro Bolívar), 355 km SSE by air (180 miles), is the nearest station to the Cumana locality, and the only one known from northeastern Venezuela. All the other Venezuelan collections recently obtained come from the extreme southwestern part of that republic in the Territory Federal Amazonas. A distance of about 3600 km or 2100 miles separates the Serra Tepequem (Terr. Rio Branco), Brazilian collection of Maguire & Maguire 40084 from the Rio de Janeiro collection localities.

Müller-Argoviensis [Mart. Fl. Bras. 6(5): 137. 1881] described the stipules of Declieuxia brasiliensis as varying from 4-7 mm in length. The specimens I have studied show a length of 2-5 mm, the longest ones of 4.5-5 mm found in Cowan & Wurdack 31539 while shorter ones of 2-3 mm long are found in the Smith et al 6408 and Riedel s n collections. The stems, rachis, and branches of the inflorescence vary from glabrous in the Riedel s n collection to minutely and moderately puberulous in the Smith et al 6408 specimen, and in both collections the leaf blades are relatively small (maximum measurements 3.1-3.5 × 0.85-1.1 cm). In the Riedel s n collection the leaves are nearly completely glabrous on both sides, whereas in Smith et al 6408 they are minutely puberulent above and less so below.

In summary, no character or characters are found to separate the widely separated and geographically isolated collections mentioned above, either specifically or sub-specifically. The first name involving these collections is the Venezuelan Tournefortia tenuiflora Willd. in Roem. & Schult., the basionym for Declieuxia tenuiflora.

Distribution:Venezuela South America| Brazil South America|