Question

describe the external and internal structure of lichen​

Answer 1

Answer:

Thalli of foliose lichens have four layers of different tissues. The uppermost layer, upper cortex, is composed of more or less vertical hyphae. ... An epidermis-like layer formed of closely packed hyphae may or may not be present external to the upper cortex. Beneath this cortical layer is algal layer.

Answer 2

Answer:

Thalli of foliose lichens have four layers of different tissues. The uppermost layer, upper cortex, is composed of more or less vertical hyphae. ... An epidermis-like layer formed of closely packed hyphae may or may not be present external to the upper cortex. Beneath this cortical layer is algal layer.