pinnate leaf

plant anatomy

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July 16, 2026

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A pinnate leaf is a type of leaf that resembles a feather. This means it has leaflets or similar parts arranged on opposite sides of a central axis, much like the barbs on a feather's rachis. This feather-like structure is considered a primitive condition in ferns.12

In plant anatomy, a pinnate leaf is a form of compound leaf where the blade is divided into leaflets along a central axis. This arrangement is common in plants like palms and ferns. The veins within a pinnate leaf typically radiate from the central axis, and in many ferns, these veins are free, meaning they do not merge.345267

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acacia
Physical description
, pinnate) appearance. In many Australian and Pacific species, the leaflets are suppressed or absent altogether, and the leafstalks (petioles) are flattened and perform the physiological functions of leaves. The leafstalks may be vertically arranged and bear thorns or sharp curved prickles at their base. Acacias…
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, pinnate) appearance. In many Australian and Pacific species, the leaflets are suppressed or absent altogether, and the leafstalks (petioles) are flattened and perform the physiological functions of leaves. The leafstalks may be vertically arranged and bear thorns or sharp curved prickles at their base. Acacias…
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fern
Shapes
…in practically all ferns is pinnate—that is, featherlike with a central axis and smaller side branches—and this is considered to be the primitive condition because of its widespread occurrence. From this basic type a broad diversity of forms evolved. Some ferns have palmate leaves (with veins or leaflets radiating from…
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…in practically all ferns is pinnate—that is, featherlike with a central axis and smaller side branches—and this is considered to be the primitive condition because of its widespread occurrence. From this basic type a broad diversity of forms evolved. Some ferns have palmate leaves (with veins or leaflets radiating from…
Read More