Systematic Position of 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)
– Abelmoschus esculentussida
Selected Indian Genera: Gossypium, Althaea, Malvestrum, Hibiscus-rosa–sinensis, Malva and Abutilon.
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.
Solitary or paired flowers or cyme like.
• Bracteolate , bracteoles forming epicalyx
•Whorl of bracteoles
• 3 to many
• 3 in Malva
• Many in Hibiscus
• Absent in Sida
• Sepals 5
• Valvate astivation
• Petals 5
• Polypetalous, fused at the base with staminal tube
• Variously colored
• Twisted or imbricate astivation
• Stamens numerous
• Filaments united forming staminal tube aroun gynoecium
• Monodelphous ( pentadelphous in Bombax)
• Reniform , monothecous and extrose anthers
• Carpels 1- many, usually 5
• multilocular/equal to no. of carpels
• 1- many ovules in each locule
• Superior ovary
• Long style united below
• Axile placentation
•Capsule (Hibiscus, Gossipium)
• Schizocarp (Sida, Malva)
Flowers are mostly insect pollinated. They are mostly attracted by the large size and bright colours of the flowers.
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.
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.
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