Vellozia asperula Mart.

Vellozia asperula Martius

Velloxia asperula Martius, Nov. Gen. & Sp., 1:15, pl. 8, 1823.—Seubert in Martius, Fl. Bras., 3(1):81, 1847.—L. B. Smith, Contr. U.S. Nat. Herb., 35:263, 1962.—Ayensu, Smithsonian Contr. Bot., 15:12, fig. 9d–f, 1974.

Vellozia asperula Martius

SPECIMENS EXAMINED.—G. Gardner 5228; Occhiouni s.n.

SURFACE VIEW.—Hairs: absent. Epidermis: adaxial and abaxial cells rectangular, thin walled. Stomata: Mainly paracytic, some tetracytic, 15 × 18 μm; present mainly on abaxial surface.

TRANSVERSE SECTION OF LAMINA.—Dorsiventral; V-shaped with median adaxial groove. Adaxial surface unevenly ridged; abaxial surface conspicuously furrowed, slightly more than one-third thickness of blade. Epidermis: cells more or less rectangular, some triangular, others almost rounded; intermitent rows of thick-walled fibers observed subjacent to epidermis, especially toward leaf margin. Cuticle: uniformly thickened on adaxial and abaxial surfaces but not observed in furrows. Stomata: present in furrows; guard cells thick walled; substomatal chamber inconspicuous. Mesophyll: adaxial palisade four to six layered, occupying about one-third of mesophyll and gradually changing into spongy tissue; two to four rows of distinctly translucent cells arranged radially above vascular bundles and furrows; rest of palisade compactly arranged and filled with chloroplast. Vascular bundles: 24, commissural bundles not observed. Large veins each with one to two, occasionally three, wide vessels. Two phloem units lying laterally in flanges of partial abaxial U-shaped girder. Each vascular bundle always accompanied by adaxial cap. Vascular bundles” completely surrounded by a distinct thin-walled bundle sheath. Crystals and tannin: not observed.

NOTE: The partial abaxial U-shaped girder recalls those of the Xerophyta type described for some of the Old World species (cf. Ayensu, 1969).