Leaf anatomical characters which contributed to most of the differences in the ten Plectranthus investigated included epidermal cell type which was sinuous or polygonal (Figures 3 and 4), trichome type which ranged from being long-stalked, short-stalked, glandular, and nonglandular to capitate (Figure 5), the nature of the leaf mesophyll which was either homogenous or
dorsiventral, and the nature of the palisade layer (Figures 3 and 4).
The
dorsiventral anatomy of the blade was observed to have a polygonal arrangement of spongy tissue consisting of typical aerenchyma, and the adaxial region of the mesophyll was occupied by homogeneous palisade parenchyma interrupted by ample substomatal chambers.
Simetria
dorsiventral. Superficie coliculada, formada por celulas poligonales, que se hacen rectangulares u oblongas sobre la quilla ventral, en las proximidades del eleosoma y en los margenes apicales, con paredes radiales no visibles y tangencial externa lisa, a veces levemente estriada y normalmente convexa (Fig.
Simetria
dorsiventral. Superficie levemente reticulada, formada por celulas poligonales, de paredes radiales superficiales y tangencial externa de lisa a levemente estriada, separadas por pliegues irregulares (Fig.
Mesophyll was
dorsiventral, with only one layer of palisade parenchyma.
A epiderme das folhas de Theobroma speciosum e unisseriada, com mesofilo
dorsiventral e parenquimas pouco distintos.
Hypostomatic leaves, paracytic stomata, straight-walled epidermal cells,
dorsiventral mesophyll and the collateral vascular system are usual characters of Rubiaceae family (Solereder, 1908; Metcalfe & Chalk, 1950).
They are usually prostrate, with a
dorsiventral thallus, 20-50 x 0.80-1.20 mm, without hairs; section of thallus shows the lamina and the border unistratose throughout; border cells have thickened walls, clearly distinct from the rest of the lamina, and single spines, 15-35 [micron]m long; the spines are sparsely distributed along the marginal cells.
As seccoes transversais da lamina foliar do biribazeiro indicam organizacao
dorsiventral das folhas, que sao do tipo hipoestomatica, com tricomas em ambas as faces (Figura 3).