Mascagnia macrodisca (Triana & Planch.) Nied.

  • Authority

    Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.

  • Family

    Malpighiaceae

  • Scientific Name

    Mascagnia macrodisca (Triana & Planch.) Nied.

  • Description

    Species Description - Woody vines; stems persistently sericeous. Lamina of the larger leaves 9-14 (-18) cm long, 4-8(-12) cm wide, elliptical or slightly ovate or obovate, cuneate or rounded at the base, short-acuminate at the apex, sericeous to soon glabrate above, persistently sericeous below with short, straight, sessile hairs, bearing below in the proximal half 1-several small glands on each side in a row parallel to but set in from the margin; petiole 10-22 mm long, persistently sericeous, usually bearing 2-8 small glands in 2 rows; stipules minute, triangular, borne at the base ofthe petiole. Flowers borne in axillary and terminal pseudoracemes or panicles, the ultimate pseudoracemes 2-9 cm long and containing 6-20(-30) flowers; bracts 1.5-3 mm long, ovate or triangular, eglandular, abaxially sericeous, adaxially glabrous; peduncle 3-5 mm long; bracteoles like the bracts but smaller, borne between the middle and the apex of the peduncle. Pedicel 3-4 mm long (-6 mm in fruit). Sepals completely concealing the petals until anthesis, ca 4.5 mm long, 1/2 connate, abaxially sericeous, adaxially glabrous, revolute after anthesis, the lateral 4 biglandular with the glands 2.5-3.5 mm long and distally free and revolute, the anterior sepal eglandular. Petals violet (or pink?), abaxially densely sericeous or tomentose, adaxially sparsely tomentose, 4.5-5.5 mm long, dentate or glandular-fimbriate, subequal. Filaments 2-3 mm long, subequal, glabrous, straight, ca 1/2 connate; anthers 1-1.3 mm long, glabrous. Styles 2.5-3.5 mm long, glabrous, straight, erect or divergent, dorsally rounded, truncate, or apiculate at the apex. Samara 4-8 cm wide, sericeous, the lateral wings membranous, 2-4 cm wide, continuous at the base or rarely divided nearly or quite to the nut, divided to the nut at the apex, sinuate, entire; central dorsal wing 5-10 mm wide, semicircular or trapezoidal, entire; intermediate winglets none; ventral areole ovate, 4-5 mm long, 3-4 mm wide.

  • Discussion

    2. Mascagnia macrodisca (Triana & Planchon) Niedenzu, Arb. Bot. Inst. Lye. Braunsberg 3: 16. 1908. Hiraea macrodica Triana & Planchon, Ann. Sci, Nat. 4 Ser. Bot. 18: 326. 1862. Mascagnia anisopetala (Adr. Jussieu) Grisebach var macrodisca (Triana & Planchon) Kostermans, Meded. Bot, Mus, Herb, Rijks Univ. Utrecht 25: 5. 1936. Type. Triana 5568-6, Villavicencio, Colombia, elev 460 m , Feb 1856 (COL! G, MO). The only collections from the Alto Orinoco (Aristeguieta & Lizot 7388 and Delascio Chitty 2220) have fruits that are atypical in that the lateral wings are partially to completely divided at the base; moreover, the petals of the former were reported to be pink. In other respects they are similar to other collections of M. macrodisca. Perhaps they represent a taxon that deserves recognition, but that must await the availability of more, better documented collections.

  • Distribution

    Distribution. Southern Venezuela, SE Colombia, and Loreto, Peru. Guayana collections: VENEZUELA. Bolívar: Pica Caicara del Orinoco-San Juan de Manapiare Km 172, 6°N, 66°W, elev 450 m, Delascio Chitty 2220 (MICH); 47 km N of Tumeremo, forest at base of Altiplanicie de Nuria, Steyermark 89315 (NY); La Prision, Medio Caura, elev 120 m, LI. Williams 11647 (F, US, VEN). Amazonas: Mavaca, Alto Orinoco, Aristeguieta & Lizot 7388 (NY, VEN). COLOMBIA. Vaupes: Rio Guaviare, San Jose del Guaviare, elev

    Venezuela South America| Colombia South America| Peru South America|