Monographs Details: Schradera clusiaefolia (Britton & Standl.) R.O.Williams & Cheesman
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Rubiaceae
Description:Latin Diagnosis - Frutex volubilis; stipulis non visis; foliis petiolatis, petiolis 5-15 mm longis; laminis oblongo-oblanceolatis vel oblongo-obovatis vel oblongo-ellipticis apice obtusis vel acutis basi acutis vel acuminatis, subrevolutis, 4.5-11 cm longis 1.2-5.5 cm latis, nervis lateralibus utroque latere 8-11 subtus plus minusve prominulis, in nervum collectivum ab margine 1-4 mm conjunctis, ultimis nervis tertiariis demum tenuissime subreticulato-elevatis, superficie subtus minutissime albo-papillata; capitulis depresso-hemisphaericis 6-7-floris 13-20 mm altis 25-30 mm latis; pedunculo solitario terminali 2-2.5 cm longo in sicco 2 mm lato vivo 4 mm lato glabro; involucro brevi 2.5-6 mm alto 6-12 mm lato glabro apice integro; calyce hypanthioque tubulosis 12-14.5 mm longis apice 5-6 mm latis glabris; calyce apice primo margine truncato delude irregulariter inaequaliterque lobato, lobis suborbiculari-rhomboideis 1.5-3 mm altis 2.5-4.5 mm latis, ab ovario ad 8 mm disjuncto; corolla alba (teste Steyermark d' Agostini) hypocrateriformi 22-26 mm longa, tubo 13 mm longo basi 3 mm lato fauce 5.5 mm lata extus glabro intus glabro superne papillato-pulverulenti; lobis 5 lineari-lanceolatis vel lanceolatis subacutis 11-14.5 mm longis 2.5 mm latis glabris, denticulo cucullato reflexo ad basin carinae ab apicem 7-8 mm; staminibus 5 exsertis, filamentis 3.5 mm longis glabris in fauce insertis; antheris 5 linearibus 5 mm longis; stylo 5 mm longo glabro; stigmatibus 2 anguste oblongis 4 mm longis.

Distribution and Ecology - TRINIDAD. Mt. Tocuche, A u g 1947, Botanic Garden Herbarium. 673 (tracing from holotype NY; holotype of Vrceolaria clusiaefolia, TRIN); same locality, 21 Jun 1906, William Leslie 9363 (holotype of Urceolaria angustifolia, TRIN, fragment of type NY). VENEZUELA. Estado Sucre: Peninsula de Paria: Cerro Patao, norte de Puerto de Hierro, noreste de Guiria; selva nublada en la cumbre plana; alt. 1020 m; climbing high in tree; stems dark purple; leaves erectascending, coriaceous, subrevolute, deep green above, pale green below; peduncle pale green, 4 mm diam; involucre lobed, pale green; corolla white, 5-lobed, lobes recurved; stamens 5; stigmas 2, pale green; calyx pale green, greenish and white above with subtruncate summit slightly slit to one side or almost 3-lobed unequally; generally 7 flowers in one head, rarely 6; 19 Jul 1962, Julian A. Steyermark d; Getulio Agostini 91074 (NY, VEN).

Discussion:

Urceolaria clusiaefolia Britton & Standi. Jour. Wash. Acad. Sci. 13: 106. 1923.

Urceolaria angustifolia Britton & Standi. Jour. Wash. Acad. Sci. 13: 106. 1923.

Schradera angustifolia (Britton & Standi.) Williams & Cheesman, Fl. Trin. & Tobago 2: 15. 1928.

Both Vrceolaria clusiaefolia and V. angustifolia were described from nonflowering specimens of plants collected on Mount Tocuche in Trinidad. A recent flowering collection (Steyermark d- Agostini 91074) from the tip of the Peninsula de Paria, Venezuela, which is adjacent to Trinidad, is conspecific with the Trinidad plants. Both the narrow-leaved (Vrceolaria angustifolia) and broadleaved (Vrceolaria clusiaefolia) types of variations are present on the collections of the Venezuela plant. A comparative evaluation between the Trinidad and Venezuelan specimens leaves no doubt but that both should be referred to the same taxon. The short peduncles, short length of involucre, spathaceous lobed calyx, similar anastomosing of the lateral nerves of the leaf blades, and a fine papillate lower leaf surface with a delicately convolute minutely mosaic-like reticulum of the tertiary venation—these characteristics are shared by the Trinidad and Venezuelan plants.

Although the fine tertiary venation seems more pronounced, at first examination, in the type collection of Vrceolaria angustifolia, it is apparent that it is likewise present on the broader leaves of V. clusiaefolia, as noted in the original description of the latter. The leaf apices in the Venezuelan collection are obtuse, as described for Vrceolaria angustifolia, whereas in V. clusiaefolia they are stated to be acute. This difference, however, is not well-marked when the holotype specimen of Urceolaria clusiaefolia is compared with the Venezuelan collection.

An emended description of the present taxon, in view of the recent Venezuelan collection in flower, follows: