Salpinga maguirei Gleason
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Authority
Maguire, Bassett, et al. 1953. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 8 (2): 87-160.
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Family
Melastomataceae
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Scientific Name
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Description
Latin Diagnosis - Caulis herbaceus 4-angulatus fere 4-alatus, densissime brunneo-lepidotus; folia petiolata ovata membranacea subacuminata; spica secunda longe pedunculata, floribus subsessilibus.
Species Description - Stems herbaceous, up to 3 dm. long, densely covered with pale brown, sessile, peltate, circular, scarious scales about 0.7 mm. wide; similar scales occur on the petioles and very sparsely on the primary veins. Leaves very thin, ovate, up to 75 mm. long by 48 mm. wide, subacuminate, obscurely crenate and with a short bristle in each sinus, at base rounded or subcordate to a triangular petiolesummit, 3-5-nerved, the nerves narrowly 2-winged beneath, naked at base of the blade, glabrous on both sides, beneath very minutely white-pustulate. Peduncle 3-5 cm. long, pale yellowish-gray, above glabrous, at base with a very few scales. Flowers as many as 7, 5-merous, apparently sessile but actually on a 10-winged pedicel about 2 mm. long and merging gradually into the hypanthium. Kypanthium narrowly obconic, glabrous, pale, about 5 mm. long, conspicuously but obtusely 10-wingedo Calyx-tube prolonged about 0.5 mm.; sepals very thin, spreading, triangular-acuminate, 4.7 mm. long from the torus. Petals pink, at least 5 mm. long. Stamens dimorphic; filaments flat, glabrous; anthers slender, the larger about 5 mm. long, the smaller about half as large; connective prolonged at base into an antrorse obtuse appendage about 1.2 mm. long and a very minute, retrorse, flattened scale.
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Discussion
TYPE: from wet cliffs on the escarpment of Cerro Sipapo, altitude 900-1200 m., Bassett Maguire & Louis Politi 27503; New York Botanical Garden. Distinguished immediately from the few other known species of the genus by its lepidote indument.
In respect to its high degree of endemism, the genus Macrocentrum is without doubt remarkable. For about a century it was known by three species only, and of these one was represented by a single specimen collected by Appun on his trip to Roraima. Within the last three decades exploration has penetrated far into the mountains of southern Venezuela, British Guiana, and Surinam, Appun's species has again been collected and no fewer than eleven others have been discovered. Most of them grow on wet rocks in the immediate vicinity of waterfalls. At present it would seem that every mountain explored has its endemic species on its own numerous cataracts, but, as a matter of fact, various species are now being found on a second, or even a third mountain, although additional local species continue to appear. The few species of the Surinam mountains are still unknown in British Guiana or southern Venezuela. Dr. Maguire collected four species on Cerro Sipapo, one of which was previously known from Duida, while three were undescribed. Two of these have a habit totally unlike any other known species, so unlike that I was unable to refer them to a genus on my first inspection. When the Duida species were first described, I drew up a key to distinguish all the species known at that time. A similar key to the fourteen species now known is presented below and reference to it is suggested for the diagnostic characters and supposed relationships of the species. It seems that the number of parts in the flower may be of little taxonomic significance, inasmuch as Dr. Maguire found 4-merous and 5-merous flowers in the same colony. The key below is based primarily on the three very different types of inflorescence found in the genus.