Mascagnia sepium (A.Juss.) Griseb.
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Authority
Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.
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Family
Malpighiaceae
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Scientific Name
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Description
Species Description - Woody vines. Lamina ofthe larger leaves 8-16 cm long, 6-8.5 cm wide, elliptical or ovate, rounded or cordate at the base, acuminate at the apex, tomentose to glabrate above except on the midrib, velutinous to subsericeous below with the hairs reddish, sessile, with erect to subappressed and often sinuous arms, occasionally glabrescent, bearing 2-4 impressed yellow glands near the base and 2-4 similar glands distally; petiole 8-16 mm long, reddish-velutinous to glabrate, eglandular; stipules ca 0.5 mm long, triangular, interpetiolar. Inflorescence axillary, 2-7(-9) cm long, shorter than the subtending leaf, a panicle of 3-5(-7) short, congested, corymbose pseudoracemes of 5-20 flowers; bracts 1-1.5 mm long, eglandular; peduncle 2-5 mm long; bracteoles 0.5-1 mm long, eglandular, borne at the middle ofthe peduncle or below or above but always well below the apex. Pedicel 7-15 mm long, sparsely but persistently sericeous or subvelutinous. Sepals appressed after anthesis, exceeding the glands by ca 1 mm, obtuse or acute, abaxially sericeous, adaxially glabrous, the lateral 4 biglandular with the glands 2.5-3 mm long, decurrent, free and slightly reflexed at the apex, the anterior sepal eglandular. Petals yellow, glabrous, exposed during enlargement ofthe bud, the laterals with limb 5 mm long and 4 mm wide, the claw ca 1.7 mm long, the posterior with a smaller limb and thicker claw. Filaments 1.5-2 mm long, glabrous, ± straight, connate only at the very base; anthers 1.2-1.5 mm long, glabrous. Ovary densely tomentose-sericeous; styles 2-2.5 mm long, green (at least at the apex), the anterior distinctly shorter and slenderer than the posterior 2, divergent, dorsally truncate or acute at the apex. Samara 1.8-3 cm high, 1.6-3 cm wide, broadly ovate to orbicular, sparsely and loosely sericeous, the lateral wing membranous, continuous at base and apex, often shallowly notched at the apex, entire or sinuate at the margin; nut eccentric i e inserted above the center of the wing; central dorsal winglet 2-5 mm wide; intermediate winglets none; ventral areole ovate, 1.5-3 mm long, 1-2.5 mm wide.
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Discussion
10. Mascagnia sepium (Adr. Jussieu) Grisebach in Martius, Fl. Bras. 12(1): 96. 1858. Hiraea sepium Adr. Jussieu in Saint-Hilaire, Fl. Bras. Merid. 3: 19. Type. St. Hilaire, Rio de Janeiro, Brazil (P). As Cuatrecasas pointed out in his Prima Flora Colombiana, Niedenzu's concept of this species was very broad. Careful study ofthe complex throughout its range may eventually allow its subdivision, but that is beyond the scope of this paper. The plants called Mascagnia sepium in northern South America are relatively homogeneous morphologically, and the description given above is based on them alone, not on the whole range of variation ofthe species. These plants have each axillary inflorescence compound and both bracteoles eglandular, unhke plants from central and southern Brazil. They are also notable for their reddish pubescence.
Distribution and Ecology: Distribution. "Argentina and Paraguay to Tobago and Honduras" (fide Niedenzu, Pflanzenreich, p 95). Collections from Guayana and nearby: BRAZIL. Amazonas: Rio Uaupes, between Ipanore and confluence with Rio Negro, Serra Wabeesee, below Bela Vista, Schultes & Pires 9142 (NY, US). VENEZUELA. Amazonas: Orinoco River, Isla del Raton, elev 90 m, Breteler 4702 (VEN, WAG). Bolivar: La Marabutana, entre Ikabaru y los Caribes, elev 400 m, Bernardi 6548 (NY); La Gran Sabana, 2 km W of Kamarata, elev 450 m, Koyama & Agostini 7257 (NY, VEN); headwaters and upper part of Quebrada CabaHape, W of Hato de Nuria, E of Miamo, elev 230-350 m, Steyermark 88663 (NY); between San Ignacio de Yuruani and San Francisco de Yuruani, S of El Dorado on road to Santa Elena, elev 1200 m, Steyermark 111399 (VEN); Rio Parguaza, 3-5 km below El Carmen, ca 50 km above river mouth, elev 110 m, Wurdack & Monachino 40941 (NY). GUYANA. Upper Rupununi River, near Dadanawa, De La Cruz 1797 (NY); vicinity of Bartica, Essequibo River, De La Cruz 1878 (NY). Collected in flower and fruit in all months.