Pulchranthus

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Pulchranthus

Description

Herbs or subshrubs. Stems terete to subquadrangular, glabrous. Leaves sessile or petiolate, narrowly elliptic to oblong, entire, undulate, or crenate, glabrous or sparsely pubescent with short, appressed trichomes, cystoliths present. Inflorescences terminal spikes to racemes, or well-branched terminal panicles with flowers in fascicles, glandular puberulent. Calyx 5-lobed, lobes narrowly triangular, glandular puberulent; corolla violet to lilac or white to pink with purplish spots, strongly 2-lipped, glandular puberulent without, tube short, broad and curved, upper lobes oblong-elliptic to oblong, lower lobes oblong to ovate or nearly orbicular, ciliate and often purplish-dotted; stamens 2, exserted, filaments curved, glabrous or pubescent, staminodes 2. Capsules clavate; seeds 4.

Distribution

French Guiana present, Guianas present, Southern America: Colombia (Colombia present), Suriname present, coastal and eastern Brazil present, eastern Peru present, low elevation forests of tropical America present
A genus of 4 species, local and infrequent in low elevation forests of tropical America, from Colombia, eastern Peru and eastward to Suriname and French Guiana and southward to coastal and eastern Brazil; in the Guianas 3 species.

Studied:

P. surinamensis.

Wood

Growth rings formed by a few rows of radially flattened fibres.
Vessels arranged in radial strokes, solitary for about 30%, remainder in radial multiples of 2-12, numerous 70 (63-75) per sq. mm, outline angular, 25-45 µm wide. Vessel member length 566 (265-785) µm. Perforations simple, intervascular pits 4 µm, slits enclosed, occasionally confluent; vessel/ray pitting identical.
Rays 1-2(-3)-seriate, 2-3 per mm. Heterogeneous, nearly all cells square or upright, the uprights up to 130 µm tall. Height of vertically fused rays about 1200 µm.
Parenchyma extremely scarce, restricted to a single strand bordering a vessel. Strands of 2-3 cells.
Ground tissue of septate fibres. Diameter 20-23 µm, walls thin, 3 µm, seldom a rhombic crystal present. Pits simple, minute, frequent in both radial and tangential walls. Length 760 (600-900) µm. F/V ratio: 1.77.