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Monday 29 September 2008

MORACEAE


Ficus benghalensis

Artocarpus lakoocha

Morus alba

Morus alba

Artocarpus incisa

Broussonetia papyrifera

FAMILY OF THE WEEK : MORACEAE
A family of 53 genera and 1400 species, mostly in tropical and subtropical regions.In India the family is represented by 15 genera and 150 species occurring mostly in tropical and sub tropical Himalayas and Assam.
Vegetative characters :
They are mostly trees or shrubs or rarely herbs as in Dorstenia. Some species of Ficus climb on other trees with the help of aerial clasping roots.
Many species of Ficus produce aerial roots which form great pillars supporting the branches. The tree attains immense size.
The leaves are alternate, rarely opposite, simple, peni-or palminerved and stipulate. The stipules are caducous and leave a scar when they fall off. they are small and lateral or intra petiolar.
Ficus krishnae has a curious cup shaped leaves.
Inflorescences and flowers :
The small flowers are basically arranged in cym0ose inflorescences which form spikes,heads disks or hollow receptacles. In Morus the male flowers are arranged in Catkins and the female in pseudo spikes. In Artocarpus the male flowers are arranged in pseudo catkins and the female in pseudo heads. In ficus a very large number of flowers are born on the inner side of a hollowed out globose or pear shaped receptacle. It has a narrow apical orifice which is closed by a small overlapping bracts.There are three types of flowers male female and gall flowers the latter are sterile female flowers. The species of Ficus are monoecious or dioecious. In the former, all the three kinds of flowers are present in the same receptacle. In dioecious species the male and gall flowers are are born in the receptacle of one plant and the female flowers in the receptacles on the other plant.
Many species of Ficus are cauliflorus, bearing flowers on old parts of trunk, while several others are geocarpic fruiting on underground stolons which arise from the baes of the trunk.
The flowers are unisexual actinomorphic and hypogynous to epigynous.
The perianth consists of usually four persistent, free or more or less united tepals which are valvate or imbricate in bud. The stamens are usually four. Sometimes they are only one or two stamens as in Ficus and Artocarpus.The anthers are versatile, dithecous and opening lengthwise.
In the female flowers the gynoecium consists of basically two syncarpous carpels. The ovary is superior(Morus) or inferior(Dorstenia). unilocular with a solitary more or less curved ovule pendulous from the apex. The styles are mostly two and filiform.
Fruits and Seeds :
The fruit is an Achene(Ficus) or a drupe(Morus). The seeds are non endospermic or endospermic and generally with a curved embryo.
Pollination and seed dispersal :
The flowers of Morus and some genera are pollinated by wind. Ficus shows an extraordinary mode of pollination by a special gall wasp.
Examples:
Morus alba,nigra,macroura,laevigata,serrata Ficus largest genus with 800 species Ficus benghalensis L. Banyan,Wad Ficus religiosa (Peepal) Ficusramosa synFicus glomerulata(Gular) Ficus infectoria(Pilkhan)
Ficus virens Ficus krishnae Ficus elastca(Indian rubber tree)
Ficus carica(Fig Anjir)
Artocarpus altilis
Artocarpus incisa
Artocarpus lakoocha

Broussonetia papyrifera
(Paper mulberry)

Tuesday 23 September 2008

MELASTOMATACEAE


Melastoma malabathricum

Memecylon umbellatum

Memecylon umbellatum buds


FAMILY OF THE WEEK : MELASTOMATACEAE

vegetative characters:

Herbs, shrubs or rarely trees. Leaves opposite, entirely of nearly so, often palmately 3-7 nerved; stipules none. Flowers regular, bisexual, in spikes, panicles or corymbs, rarely solitary or clustered. Calyx-tube adnate to the ovary and more or less prolonged beyond it; limb 4-5 lobed, lobes deciduous. Petals as many as the calyx-lobes, on the margin of the calyx-limb. Stamens as many or twice as many as the petals, inserted with them; filaments inflexed in the bud; connective generally prolonged and often much enlarged. Ovary 4-5 celled (in Memecylon 1-celled); ovules very many (except in Memecylon); seeds minute, very many (in Memecylon one only).

Leaves palmately 3-7 nerved. Stamens unequal, seeds many--MELASTOMA.

Leaves penninerved. Stamens equal, seed one--MEMECYLON.

Examples:
Melastoma malabathricum.

Memecylon umbellatum(Anjani)

MELIACEAE






FAMILY OF THE WEEK : MELIACEAE
(MAHOGANY FAMILY)
The Mahogany family contains 50 genera and 1400 species distributed exclusively in the tropical regions of the world. In India there are 19 genera and 72 species occurring mostly in the peninsular India.
Vegetative characters:
They are mostly trees and shrubs, often with hard and scented wood.
The leaves are alternate, exstipulate and usually pinnate or rarely 3-pinnate(Melia azadirachta) or simple(Turraea). The leaflets are opposite or alternate., usually entire and more or less oblique at the base.
Inflorescence and flowers :
The inflorescence is usually an axillary cymose panicle.
The flowers are actinomorphic, hermaphrodite and hypogynous.
The calyx is composed of 3-6 sepals which are united or rarely free.
The corolla is also composed of 3-6 petals which are free or rarely connate at the base.
The androecium has four to 12 stamens which are inserted outside the base of the hypogynous disc. The filaments are mostly connate in a tube(monadelphous) but they are sometimes free as in Cedrela and Chloroxylon. The anthers are sessile on the staminal tube, included or axserted, dithecous, introrse and dehiscing longitudinally. A nectariferous disc is often present between the stamens and the ovary. The gynoecium is two to five carpellary and syncarpous with a superior two to five locular ovary. The style is short or absent and the stigma is discoid or capitate.
Fruits and seeds :
The fruit is loculicidal or septicidal capsule or sometimes baccate or drupaceous.
Pollination is usually by insects which visit them for nectar.
The winged seeds of toona are dispersed by wind. In others the dispersal may be by bats and birds or by squirrels.
Examples:
Swietenia mahogani (West Indies Mahogany)
Swietenia macrophylla
Khaya senegalensis (African Mahogany)
Toona ciliata Chickrassia tabularis (Chittagong wood)
Chloroxylon swietenia(Satin wood)
Azadirachta indica(Neem)Kadulimb
Melia azedarach(Bankayan)Bakana nimb
Melia dubia(कडू खजूर; निम्बारा )
Aphanamixis polystachya syn. Aphanamixis rohituka syn.Amoora rohituka

Wednesday 10 September 2008

MALVACEAE


Kydia calycena



Dombeya acutangula

Abutilon persicum

Abelmoschus manihot

Sida acuta




Abutilon indicum



FAMILY OF THE WEEK : MALVACEAE
In India the family is representaed by 22 genera and 110 species occurring mostly in warmer parts.Benthem and Hooker divided the family into four subfamilies, Malveae,Ureneae,Hibisceae and Bombacaceae. Bommbacaceae is not covered here as it has been explained elsewhere.
Vegetative characters :
The members are mostly annual or perennial herbs, but in the tropics they are shrubs or rarely soft wooded trees. The stem is fibrous with inner bark often tenacious. The herbaceous portions are often more or less covered with stellate hairs.
The leaves are alternate, simple,entire.
Inflorescence and flowers :
The inflorescences are either axillary, solitary, or fascicled and often form long terminal racemes.
The flowers are hermaphrodite or rarely unisexual or polygamous, actinomorphic, pentamerous and hypogynous.
The calyx is frequently subtended by an involucre of bracteoles which form the epicalyx. It protects the younf flower bud. The calyx is usually of five, free or connate sepals which show valvate aestivation. The corolla has five petals which are often large and showy, free or basally connate with the staminal coloumn as in Hibiscus. The petals show twisted or imbricate aestivation.
The androecium has numerous stamens which are monadelphous. The filaments are united to form a staminal coloumn around the ovary. The staminal cploumn is divided at the apex and bears reniform monothecous anthers.The pollen grains are covered by spines.
The gynoecium is of two to many fused carpels which are arranged in a whorl around the central axis. The ovary is superior.
Fruits and seeds :
The fruit is loculicidal capsule as in Hibiscus and gossipium or more often it is a dry indehiscent, In sida, Malva and Abutilon schizocarps separate from one another and from the persistent central axis and each one seeded or occasionally two to many seeded as in some species of Abutilon. The seeds are reniform or obovoid with scanty endosperm . They are often pubescent or densely clothed with wooly hairs as in Gossipium.
The flowers are mostly insect pollinated.The seeds of gossipium are dispersed by wind. In some species such as Urena lobata the seeds have hooked spines which are dispersed by adhesion to animals and human.
Examples:
Gossipium (Cotton):(Marathi: Kapus)extensively cultivated in the tropics for fibre. The cultivated forms arise mainly from G.barbadense and G.hirsutum(America) and G.arboreum and G.hirbaceum in India, Egypt and other countries.
Several species are grown as ornamentals:
Hibiscus rosasinensis
Hibiscus schizopetalous
Hibiscus sabdariffa
Hibiscus mutabilis
Hibiscus esculentus(Lady's finger,Okra,Bhendi) used as vegetable.
Sida cordifolia
Sida acuta
Sida rhombifolia
Abutilon
Urena lobata
Thespesia lampas
Thespesia populnea
Kydia calycena

Tuesday 2 September 2008

MAGNOLIACEAE


Talauma mutabilis

FAMILY OF THE WEEK :MAGNOLIACEAE

A small family with 230 species in the world mostly distributed in tropical Asia and tropical America but extending to north temperate zone. In India there are 8 genera and 27 species mainly in north temperate zone in the Himalayas.

Vegetative characters :

The Magnoliaceae are evergreen or deciduous trees often aromatic trees or shrubs but sometimes woody climbers.

The leaves are alternate, simple, entire and stipulate. The leaves are sometimes clustered at upper nodes as in Illicium. They are often pellucid dotted. The stipules are large and deciduous, enclosing next young bud.

Inflorescence and flowers:

The flowers are usually solitary, terminal or axillary; sometimes they are crowded near the tips of the branches. They are subtended by a spathaceous deciduous bract. The flowers are showy and large, actinomorphic and usually hermaphrodite and hypogynous with an elongated floral axis on which floral parts arranged spirally.

The perianth is differentiated or undifferentiated into calyx and corolla.

The numerous free stamens are arranged on the conical receptacle. The anthers are adnate or basifixed, dithecous introrse or sometimes extrorse and opening longitudinally.

The numerous free carpels are arranged spirally on the floral axis above the stamens.

The ovary of each carpel is superior, unilocular with one to several anatropous or amphitropous ovules on ventral suture. The style is usually short and stigmatose on the inner surface.

Fruits and seeds :

The individual flower is a follicle(Magnolia) or Samara (Liriodendron) or berry (Schizandra)

Flowers are pollinated by bees and beetles.Dispersal of seeds takes place by birds,squirrels,rats or monkeys which carry off fruits.

Examples :

Magnolia

Michelia

Liriodendron

Talauma mutabilis (कवठी चाफा )