L. Michael Hill

Biology 207 and 420,425

Monocots vs Dicots

The flowering plants are divided into two groups.  The Monocotyledonae and the Dicotyledonae.  Below are the five most basic differences that are, for the most part, rather predictive and visible.  Some of these are linked to further discussion.  Also, in the end, click here for a self-examination of this concept.

 

Monocot Classification Dicot

6petals.jpg (32129 bytes)

3's or multiples of 6, rarely more than six

Flower Parts

4, or 5, or multiples up to 10

monocotdicot10.jpg (34590 bytes)

parallelveins2.jpg (63079 bytes)

Parallel Venation

Leaf Venation

Netted Venation

nettedvenation.jpg (42132 bytes)

Zeastemview1.jpg (31691 bytes)

Monocots have scattered vascular bundles throughout the stem.

Internal Stem Anatomy

 

Dicots have vascular bundles only on the perimeter of the stem.

Helianthusstemview1.jpg (58672 bytes)

cornseedmonocot.jpg (13606 bytes)

Normally the one cotyledon never emerges in germination, being used up by the growing embryo.

 

Number of Cotyledons Typically,  you can see the two cotyledons when some seeds of this group germinate.  They provide energy for early growth, but dry up as photosynthetic leaves are produced.

beanseedcotyledon1.jpg (28308 bytes)

fibrousroot.jpg (58478 bytes)

In the Fibrous root system of Monocots, the primary root is almost non-existent. The secondary roots are important in absorption, but are not as deep as the primary root of most dicots. Root System The Tap root system is deep with a long primary root.  Less important secondary roots branch off.

taproot.jpg (97344 bytes)