Malvaceae : Morphological Diversity of Families : Dicotyledons

Malvaceae : Morphological Diversity of Families : Dicotyledons

Malvaceae

Systematic Position of Malvaceae

Class:  Malvaceae

Subclass: Polypetalae

Series: Thalamiflorae

Order: Malvales

Family: Malvaceae

Distribution: Malvaceae is a small family containing 75 genera and about 1000 species distributed world wide. About 22 genera and 110  species have been reported from India.

common examamples are:


Hibiscus rosa-sinensis( china rose)

Gossipium(cotton)


– Malva

  – Abelmoschus esculentussida

Selected Indian Genera: Gossypium, Althaea, Malvestrum, Hibiscus-rosasinensis, Malva and Abutilon.

Vegetative characters:

Root: Branched Taproot

Stem: Herbaceous, woody, branched and erect.

Leaves: Simple or palmately compound sometimes lobed to divided. Palmately or pinnately veined, usually spiral and stipulate.

Floral characters:

Inflorescence:

Solitary or paired flowers or cyme like.

Flowers:F

• Bracteate

• Bracteolate , bracteoles forming epicalyx

• Pedicellate

• Complete

• Bisexual

• Actinomorphic

• Hypogynous

• Pentamerous

EPICYLAX

•Whorl of bracteoles

• 3 to many

• 3 in Malva

• Many in Hibiscus

• Absent in Sida

Calyx:

• Sepals 5

• Gamosepalous

• Valvate astivation

Corolla:

• Petals 5

• Polypetalous, fused at the base with staminal tube

• Variously colored

• Twisted or imbricate astivation

Androecium:

• Stamens numerous

• Filaments united forming staminal tube aroun gynoecium

• Monodelphous ( pentadelphous in Bombax)

• Reniform , monothecous and extrose anthers

• Epipetalous

Gynoecium:

• Carpels 1- many, usually 5

• Syncarpous

• multilocular/equal to no. of carpels

• 1- many ovules in each locule

• Superior ovary

• Long style united below

• Axile placentation

Fruit:

•Capsule (Hibiscus, Gossipium)

• Schizocarp (Sida, Malva)

Pollination:

Flowers are mostly insect pollinated. They are mostly attracted by the large size and bright colours of the flowers.


inflorecence of Malvaceae

Hibiscus rosa sinensis

Habit: perennial shrub reaching a height of 8-10 feet.

Root: Branched tap root with nodules containing nitrogen fixing bacteria.

Stem: Aerial, erect, branched, solid, cylindrical and woody.

Leaf: Ramal and cauline, simple, petiolate, alternate, stipulate, ovate, margin serrate, apex acute, venation reticulate unicostate.

Inflorescence: Solitary axillary flowers with jointed peduncles.

Flower: Pedicillate, ebracteolate, complete, actinomorphic, cyclic, bisexual, protandrous and hypogynous.

Epicalyx: 6-8, free forming a whorl outside the calyx, linear, hairy.

Calyx: Sepals 5, gamosepalous,valvate aestivation, persistent and green.

Corolla: Petals 5, polypetalous fused at the base with stamina tube, aestivation twisted, various shades of red and other colours and mucilaginous.

cylax of Malvaceae

Androecium: Stamens many, monoadelphous. The staminal tube surrouds the style and red in colour. Another yellow, extrose, dehiscing longitudinally.

Gynoecium: Ovary superior, pentacarpellary, syncarpous, pentalocular with many ovules in the axile placenta. Style tubes fused at the base free above with 5 stigmatic surfaces. The stigma is velvety and red in colour.

Fruit: 5 valved, loculicidal capsule.

Seed: Albuminous, hairy.

androecium, gynoecium, fruit, seed of Malvaceae


Floral formula:

To know about Fabaceae (Leguminosae) : Morphological Diversity CLICK HERE

To know about Brassicaceae (Cruciferae)/Mustard Family : Morphological Diversity CLICK HERE 

To know about Ranunculaceae : Morphological Diversity Of Families : Dicotyledons CLICK HERE

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