| Sori numerous, rather near the midvein, stipe and rachis lustrous brown. |
| Soon after the cells of the marginal meristems begin to divide, procambial strands differentiate into the leaf from the stem bundles to form the midvein, or midrib. |
| Its leaves are dull green with toothed margins and a raised midvein on the underside. |
| Only the midvein and some large lateral veins have any secondary growth. |
| Since the midvein is at the center of the images it is clearly shown that the leaves curl toward their adaxial surface. |
| The depression is formed by the midvein on one side of the nectary and a secondary vein on the opposite side. |
