TESTA EPIDERMIS
Testa epidermal cells form the epidermal layers of such seeds as lobelia, henbane, capsicum, paprika, larkspur, belladonna, scopola, etc.
In surface view the end walls are thick and wavy in outline; frequently the line of union—middle lamella—of two cells is indicated by a dark or light line, while in others the wall between two cells appears as a single wall. The walls are porous or non-porous, and the color of the wall varies from yellow to brown, to colorless. These cells always occur in masses, composed partially of entire and partially of broken fragments.
In lobelia seed (Plate 4, Fig. 2) the line of union of adjacent cell walls appears as a dark line. The walls are wavy in outline, of a yellowish-red color and not porous.
In henbane seed (Plate 4, Fig. 3) the line of union between the cells is scarcely visible; the walls are decidedly wavy, more so than in lobelia, and no pits are visible.
In capsicum seed (Plate 4, Fig. 1) the cells are very wavy and decidedly porous, the line of union between the cell walls being marked with irregular spaces and lines.
In belladonna seed (Plate 5, Fig. 1) the walls between two adjacent cells are non-striated and non-porous, and extremely irregular in outline.
PLATE 4
Testa Epidermal Cells
1. Capsicum seed (Capsicum frutescens, L.).
2. Lobelia seed (Lobelia inflata, L.).
3. Henbane seed (Hyoscyamus niger, L.).