Aristolochia gracilipedunculata F.González
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Authority
González G., Favio. 2011. A new pseudostipule-bearing species of
(Aristolochiaceae) from Bahía and Espíritu Santo, Brazil. Brittonia. 63 (4): 430-435. -
Family
Aristolochiaceae
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Scientific Name
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Description
Description - Slender vines to 3 m long, glabrous, with tiny glandular dots (under the dissecting micro scope) on stems, leaves, and perianth. Petioles 2-3.6 cm long, glabrous; leaf blade ovate to narrowly ovate, 8-14x3.2-6.6 cm, glabrous, membranous, base deeply cordate, not peltate, yellowish above (ex sicco), sinus 1—1.6 cm deep, lobes parallel to slightly convergent, apex acute, margin entire, venation palmate-reticulate, flat or slightly prominulous on both sides, primary veins 5, basal, forming with the higher order veins a fine and conspicuous reticulation; pseudostipules broadly ovate, slightly falcate on lateral view due to clasping condition, 1-3 x 1-2 cm, glabrous, sessile. Peduncle plus ovary 6-17 cm long, filiform (<1 mm in diameter), glabrous; ovary ca. 1 cm long, glabrous, slightly rostrate, rostrum <1 mm long. Perianth glabrous on the outer surface, yellow with purple to maroon spots and veins; utricle broadly obo void, 1.6-2.3 X 0.7-0.9 cm, tube cylindrical, strongly reflexed and forming an acute angle with respect to the utricle, 1-1.8x0.4—0.6 cm, limb oblong to broadly obovate, 1.8—2x1— 1.5 cm, ascending during early anthesis, cucul late at late anthesis, unilobed, erect, base truncate, apex round to emarginate, mucronu late, ecaudate, margins and fauces with fim briae 1.5-2.5 mm long; gynostemium 4—6 mm long. Capsule broadly cylindrical, 1.7—2.5 x 1— 1.7 cm, green, glabrous, transversely striate (ex sicco), apex not rostrate. Seeds ovoid, 6 x 5 mm, not winged, lateral vertices obtuse, adaxially almost totally covered by a prominulous raphe with a membranous extension, abaxial surface and margins scattered warty.
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Discussion
Distribution.-The new species is known to occur in Bahía and Espíritu Santo, Brazil. It grows either within or on the border of semi deciduous forests or in "mata en regeneraçào, umido" {Demuner et al. 2119), in an "aflora miento rochoso" (Demuner et al. 3517).
Etymology.-The specific epithet makes reference to the long, filiform peduncle.
Aristolochia gracilipedunculata is easily recognizable by the presence of a long, filiform peduncle (Fig. 1), and by the oblong, fimbriate perianth limb with a rounded and emarginate apex (Fig. 2 A). This combination of characters is unique to the new species.
The flowers of the new species resemble those of Aristolochia melanoglossa Speg., from dry forests and thickets of southern Bolivia (Chuquisaca) and northern Argentina (Salta and Tucumán) between 800-2000 m. However, the perianth of A. melanoglossa terminates in a narrowly ovate, efimbriate and erect limb, the tube is narrower and funnel form, the peduncle is stout and shorter (4.0 8 cm long and ca. 1.5-2 mm in diameter), the young leaves are hirtellous above, and the pseudostipules are not clasping and are much smaller (to 5x5 mm).
In lateral view, the perianth of Aristolochia gracilipedunculata resembles that in A. mos sii S. Moore and A. tamnifolia (Klotzsch) Duchartre. However, in these two species, the pseudostipules are lacking. Furthermore, flowers of A. mossii differ in having a longer utricle (2—4 cm long), and a larger (5-3 x 2-4 cm) and broadly-ovate limb, which is not cucullate and distally differentiated into an ovate process 4-12 mm long x 3-6 mm wide; in addition, capsules of A. mossii are much longer (6-8 cm long), ng), and contain seeds that are winged and larger (6-10x4-8 mm). The second species, A. tamnifolia, also from Brazil, differs by having a much shorter peduncle (2.5-3.2 cm long), flowers with a funnelform, narrower tube (2-3.5 mm prox imal diameter and 5-7 mm distal diameter) and a broadly oblong to broadly ovate limb, which is densely covered with longer (to 1 cm long) and stout fimbriae at its margins and inner surface; A. tamnifolia also has longer capsules (4-5.5 cm long). Nine species of Aristolochia from Bahía and Espíritu Santo, Brazil, belong to the Pseudostipulosae group.