Fig. 6.

Diversity of stomatal morphology in bryophytes. (A) Young sporangium of the moss Bryum capillare with numerous stomata scattered in the neck region. (B) Detail of sporangial wall in the moss Orthotrichum anomalum, showing a sunken stoma overarched by projections from adjacent epidermal cells. (C) Non-functional stomata in the moss Sphagnum fimbriatum. (D) Densely arranged stomata raised above the epidermis in the sporangium of the moss Polytrichastrum formosum. (E) A stoma in the sporangial wall of Anthoceros punctatus; the guard cells are covered with hydrophobic material that possibly prevents water entry into the substomatal cavity.