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Chapter 3. Plant Cells and Tissues
Leaves (forms)

Leaf Shapes, Margins, Apices, and Bases

Simple, Angiosperm Leaves

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

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


Botanical Terms

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