The Structure of Petioles in Pteris (Pteridaceae)

• DOI: 10.1640/0002-8444-102.1.1
• Publication Date: 2012-07-16T13:52:45Z
• Authors: Olga G. Martínez; Ignacio Vilte
• Keywords: Pteridaceae; Petiole (insect anatomy); Pericycle; Endodermis; Liquidambar styraciflua; Indumentum; Pteris vittata; Parenchyma

We studied the petiole structure of twelve American species Pteris P. ciliaris, cretica, deflexa, denticulata, ensiformis, exigua, inermis, multifida, mutilata, quadriaurita, tristicula and vittata, using both light scanning electron microscopy. found that petioles are characterized externally by presence an adaxial groove two dorsal-lateral ventilation areas. Internally, monostelic V-, U- or inverted-Ω-shaped axes. The vascular system is surrounded one endodermis cell layer 1–3 pericycle strata. propose a classification bundles into four types considering their shape, shape xylem ends, number protoxylem zones parenchyma bands in xylem.