Magazine - Dicot & Monocot

By Simon Kars in Consultancy on 26th May 2008 6:00

Standard distinctions between dicots and monocots are quite useful. However there are many exceptions to these characters in both groups, and that no single character in the list below will infallibly identify a flowering plant as a monocot or dicot. Take a Pine tree for example who then falls into the conifer family as it does not produce a flower. Lets have a look at what makes a Dicot and a Monocot.

All dicots and monocots are flowering plants, and so are descended from flower-producing plants. The flowers are not always large and showy the way we expect flowers to be. Oaks, maples, and elms are all dicot trees, but they do not produce obvious flowers.
Grasses, Rushes, and pond weeds are all grouped in the monocots whose flowers are often overlooked because they do not have sepals or petals.

MONOCOTS                                                             DICOTS
Embryo with single cotyledon                    Embryo with two cotyledons
Pollen with single furrow or pore              Pollen with three furrows or pores
Flower parts in multiples of three             Flower parts in multiples of four or five
Major leaf veins parallel                              Major leaf veins reticulated
Stem vacular bundles scattered               Stem vascular bundles in a ring
Roots are adventitious                                Roots develop from radicle
Secondary growth absent                          Secondary growth often present

A Example of Both is Below

Monocot Species
Botanical Name: Cynodon dactylon
Common Name: Couch, Common Couch
Plant Family: Poaceae
Plant Description
Cynodon dactylon is an evergreen, strongly stoloniferous warm season turf grass, which originates from East Africa and grows to approximately 5cm × 200cm in size. Cynodon dactylon is largely prostrate, forming a tight sod with dark green leaves that have a fine texture and turn brown during dormancy. Cynodon dactylon spreads by both stolons and rhizomes. The flowers are 4 to 5 digitate panicles with 5 branches and are present during Dec, Jan, Feb and Mar months. The fruit is a pericarp fused with a very small seed (caryopsis). Cynodon dactylon can produce up to 3,960,000 seeds per kg during Feb, Mar, Apr and May months. This hardy long-lived turf grass is used in domestic gardens, playing fields, golf courses and has become a weed in bushland areas. It is an excellent lawn with leaf blades that are soft, smooth too partially hairy. It tolerates close mowing and gives a good cover. Cynodon dactylon is controlled by chemical application, which must comply with current recommendations.

Dicot Species
Botanical Name: Modiola caroliniana
Common Name: Red Flower Mallow, Carolina Mallow
Plant Family: Malvaceae
Plant Description
Modiola caroliniana is a fast growing, evergreen soft wooded perennial, which originates from South America and grows to approximately 0.2m × 0.4m in size. Modiola caroliniana has a prostrate creeping habit with stems rooting at the nodes and in warmer climates it is regarded as a lawn weed. The leaves are small and sub-orbicular in shape with sparsely covered minute stellate hairs on both the leaves and stems. The flowers are tiny and occur on short stalks with 5 petals during Oct, Nov, Dec, Jan and Feb months. During Feb, Mar, Apr and May months Modiola caroliniana fruits an orbicular schizocarp with a whorl of 20 carpels each containing 2 seeds, which are dispersed by water and gravity. This resilient plant is found in wastelands, garden beds and in lawns. Modiola caroliniana is removed by hand using a small knife or poisoned with 1% glyphosate and requires follow up weeding.

Read more articles in Consultancy, by Simon Kars or from May 2008.