Botany/Leaves (forms)

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Chapter 3. Plant Cells and Tissues
Leaves (forms)

Leaf Shapes, Margins, Apices, and Bases edit

Simple, Angiosperm Leaves edit

This page presents the terminology used to describe the shapes and forms of leaves. The following examples are all simple leaves. All are from flowering plants (angiosperms). Descriptive terms are given for the lamina shape (that is, its overall shape in outline), the lamina margin, the form or shape of both the apex (tip) and the base (lamina junction with petiole) of the leaf, and (in some cases) other qualities evident in the example picture presented.

1. Chamaesyce celastroides (EUPHORBIACEAE) 1. 'Akoko SHAPE: oblong to elliptic MARGIN: entire TIP: retuse BASE: rounded	3. Ageratina riparia (ASTERACEAE) 2. Mist flower SHAPE: rhombic MARGIN: serrate TIP: attenuate BASE: cuneate
2. indet. (?LAMIACEAE) 3. indet. SHAPE: ovate MARGIN: crenate TIP: acute BASE: ~ rounded OTHER: color bright green	4. Ficus religiosa (MORACEAE) 4. Bo tree SHAPE: cordate MARGIN: entire, slightly undulate TIP: caudate BASE: cordate
Macadamia sp. (PROTEACEAE) 5. Macadamia nut SHAPE: linear MARGIN: undulate and spinose TIP: (not visible) acute	Richardia brasiliensis (RUBIACEAE) SHAPE: MARGIN: lobes ciliate TIP: acute
(CYPERACEAE) SHAPE: linear MARGIN: entire TIP: acute	Coronopus didymus (BRASSICACEAE) SHAPE: oblong in outline, deeply pinnatifid MARGIN: lobes dentate TIP: (not visible) acute
Ammania auriculata (LYTHRACEAE) SHAPE: linear MARGIN: entire TIP: acute	Myriophyllum aquaticum (HALORAGACEAE) SHAPE: pinnatifid, segments capillary MARGIN: N/A TIP: N/A BASE: N/A OTHER: leaves whorled
Brachiaria mutica (POACEAE) SHAPE: linear MARGIN: entire TIP: acute OTHER: Base sheathing

Compound, Angiosperm Leaves edit

These examples are all compound leaves. In these leaves, it is not always very instructive to describe the "leaf outline" and better to describe the number (or range) of leaflets. If the number is odd, there will be an unpaired leaflet at the tip. The shape terminology can be applied to the individual leaflets.

Canavalia sericea
(FABACEAE)

Silky jackbean
SHAPE: orbicular to elliptic
MARGIN: entire
TIP: obtuse
BASE: obtuse

Toona ciliata
(MELIACEAE)

Australian redcedar
SHAPE: lanceolate to elliptic
MARGIN: entire
TIP: cuspidate
BASE: oblique

Links edit

Botanical Terms