Barbacenia graciliflora L. B. Sm.

Barbacenia graciliflora L. B. Smith

Barbacenia graciliflora L. B. Smith, Contr. U.S. Nat. Herb., 35:281, pl. 10: figs. 27, 28, 1962.

TYPE.—On rocks at edge of stream, sandstone area, Serra de Monjolo, 18 km north of Sêrro, Mun. Sêrro, Minas Gerais, Brazil, 5 May 1945, Williams & Assis 6816 (GH, holotype).

DISTRIBUTION.—Known only from the type-collection.

83. Barbacenia pulverulenta L. B. Smith & Ayensu, new species

A B. ensifolia Martius ex Schultes f., cui verisimiliter affinis, foliis scapum multo superantibus, perianthii glandulis minimis pallidis differt.

Caudex over 6 cm long, completely covered by reflexed leaves. Leaf-sheaths wholly covered; blades linear, filiform-attenuate, 13 cm long, 5 mm wide, sulcate on both sides, grayish green from a dense coat of vitreous glands ca. 0.05 mm long.

Scape 4 cm long, microscopically pale-glandular. Flower vestite like scape, orange (!Menezes). Ovary slenderly turbinate, ca. 25 mm long, barely distinct. Perianth-tube (whole) slenderly subcylindric, 55 mm long, 3 mm wide. Tepals oblong, contracted toward base, rounded and apiculate at apex, 15 mm long, 2.5 mm wide. Anthers not seen; coronoid appendages (incomplete) subtriangular, 5 mm long without lobes. Style exceeding the tepals, the apex ellipsoid and completely covered by the stigmas.

LEAF ANATOMY (Menezes 245).—Surface View: Hairs: small hairs present on abaxial surface. Epidermis: cells on both surfaces square to rectangular; walls slightly thickened. Stomata: paracytic and tetracytic; 18 × 15 μm; present in abaxial furrows only.

Transverse Section of Lamina: Dorsiventral; almost horizontal. Adaxial surface ridged; abaxial surface furrowed about ½ thickness of blade. Small hairs present on abaxial surface. Epidermis: cells rounded to dome-shaped; walls slightly thickened; cells larger above midvein. Cuticle: thick and ridged on both surfaces. Stomata: present in abaxial furrows only; stomata raised above the surface of epidermis and protected by two large, protruding subsidiary cells on either side; fairly large substomatal chamber present. Mesophyll: in area not above furrows occur one or two layers of slightly elongated palisade cells followed by 7 layers of rounded, compactly arranged cells. Above the abaxial furrows are 2 or 3 layers of thick-walled cells followed by 3 layers of rounded, compactly arranged cells. Two layers of cells above midvein elongated and thick-walled. Vascular bundles: 23; commissural bundles observed. One or two large vessels present in each bundle, mostly one. Two phloem units lying laterally in flanges of very short Y-shaped abaxial girder; girder extends laterally along the abaxial epidermis with the tips curving adaxially. Adaxial girder is T-shaped becoming wider near the epidermis and extending laterally along it. Lateral extensions of adaxial girder are continuous with thick-walled cells above the furrows. No adaxial girder on midvein. Bundle sheath completely surrounding each vascular bundle. Crystals: none observed. Tannins: many present.

Note: This species is characterized by the extensive development of abaxial sclerenchyma girder and the distinctly shaped furrows.

TYPE.—Near kaolin mine, km 114, to the left (west) of the road from Lagoa Santa to Conceição do Mato Dentro, Serra do Cipó, Minas Gerais, Brazil, 24 July 1972, Menezes 245 (US, holotype; SPF, isotype).

DISTRIBUTION.—Known only from the type-collection.