Terminology
Leaf Shapes
The width of each basic leaf shapes can be described as narrowly- or widely-, depending on the degree of modification from the standard shapes. Plants with leaves that have more than one shape are called heterophyllous.
- Linear
- Long and narrow, with essentially parallel margins.
- Lanceolate
- Widest below the middle of the blade and 3 to 6 times as long as wide.
- Ovate
- Widest below the middle of the blade and about 1.5 to 2 as long as wide.
- Elliptic
- Widest at the middle of the blade, with curved margins and pointed apex and base.
- Oblong
- Rectangular, with nearly parallel margins, about 2 times as long as wide.
- Oval
- Widest at the middle of the blade, with curved margins and rounded apex and base.
- Rhombic
- Diamond-shaped, widest at the middle and with straight margins.
- Deltoid
- Triangular, shaped roughly like an equilateral triangle.
- Oblanceolate
- Reverse lanceolate, widest above the middle of the blade.
- Spatulate
- Spoon-shaped, basically oblanceolate, but with a narrow (attenuate) base.
- Obovate
- Reverse ovate, widest above the middle of the blade.
- Orbicular
- Circular, with rounded sides.
- Scale-Like
- Reduced in size, flat and sharp-pointed or blunt.
- Subulate
- Awl-shaped, narrow and pointed, rounded in cross section.
- Acicular
- Needle-like, very narrow and pointed, rounded in cross section.
- Runcinate
- Oblanceolate with lacerate margins.
- Fan-Shaped
- A leaf with the blade spreading out in a semi-circle.
- Peltate
- A leaf with the petiole attached near the centre of the undersurface of the blade.
- Cordate
- Heart-shaped, with a pointed apex and 2 rounded basal lobes.
- Obcordate
- Reverse heart-shaped, with a narrow base and 2 rounded apical lobes.
- Reniform
- Kidney-shaped, with a broad rounded apex and 2 rounded basal lobes.
- Sagittate
- A leaf with pointed basal lobes directed downwards or inwards.
- Hastate
- A leaf with pointed basal lobes divergent or directed outwards.
- Auriculate
- A leaf with small rounded (ear-like) lobes at the base.
- Lyrate
- Lyre-shaped, basically oblanceolate, with 2 or > pairs of smaller lower lobes.
- Panduriform
- Fiddle-shaped, basically oblanceolate, with 2 small lower lobes.