FIGURE 2 in A taxonomic monograph of the fern genus Ctenitis (Dryopteridaceae) in South America

FIGURE 2. Transversal sections of petiole bases of four Ctenitis species from South America. A: C. nigrovenia, showing three vascular bundles (Salino 15212, BHCB). B: C. christensenii, showing four vascular bundles (Salino 13408, BHCB). C: C. laetevirens, showing five vascular bundles (Schimitt 561, BHCB). D: C. nervata, showing six vascular bundles (Almeida 1682, BHCB). Scale bars = 1 mm.