FAMILY OF THE WEEK : LYTHRACEAE

Lagerstroemia microcarpa




Lagerstroemia

Woodfordia

FAMILY OF THE WEEK : LYTHRACEAE

In India 13 genera and 50 species occur throughout tropical India.

The common examples are pomegranate, Henna and crape myrtle.

Vegetative characters:

Herbs shrubs or trees.

The important anatomical feature is the presence of bicollateral vascular bundles in the stem.

The leaves are usually opposite or sometimes whorled, simple and entire.

The stipules are absent or very small.

Inflorescence and flowers:

The flowers are terminal and solitary or cymose or axillary solitary or in small trichotomous cymes or in racemes or in panicles.

The flowers are actinomorphic or sometimes zygomorphic as in Cuphea, hermaphrodite, usually four-,six-,or eight-merous and peri or epigynous.

Usually a hypanthium is present from which sepals petals and stamens appear to arise.

The sepals are four six or eight springing from the margin of the hypanthium. The aestivation is valvate.

The hypanthium is frequently subtended by an epicalyx of connate bracts. The petals are as many as the sepals. The stamens are usually twice as many as the petals and are inserted below the petals. In Punica and Lagerstroemia they are numerous and are in many whorls. The gynoecium is two to six carpellary and syncarpous.

Fruits and seeds:

The fruit is usually a capsule dehiscing transversely or by valves or irregularly. In Punica it is a berry with a thick and leathery pericarp. The seeds are non endospermic and with a straight embryo. In Punica the outer seed coat becomes pulpy and it contains juice.

Pollination and seed dispersal:

The flowers are pollinated by bees which visit them for nectar which is collected in lower part of the hypanthium tube. The seeds are dispersed by wind water or by birds and animals.

Examples:

Lagerstroemia flos –reginae (syn) L. speciosa. (Queen crape myrtle)Tamhan

Lagerstroemia indica(Crape myrtle)

Lagerstroemia parviflora

Lagerstroemia lanceolata

Lawsonia inermis(syn)L.alba (Henna, Mehendi)

Punica granatum(Pomegranate)

Woodfordia fruticosa(Dhayti)

LORANTHACEAE

FAMILY OF THE WEEK: LORANTHACEAE -- MISTLETOE FAMILY
Around 1300 species are observed throughout the world mostly distributed in tropical and temperate regions.In India the family is represented by 11 genera and 50 species mostly in western ghats and tropical and subtropical Himalayas.The familiar examples are Mistletoe (Viscum) and Banda (Dendropthe falcata)

Vegetative characters:
The plants are mostly semiparasitic shrubs which derive a considerable part of nourishment from the host tree. They are attached to the host with the help of modified adventitious roots (haustoria) which penetrate the bark and sapwood of the host. They attack a wide range of trees.
The stem is sympodial and often dichotomous. In Viscum the terminal bud ends in an inflorescence whereas the lateral buds continue to grow in next season.The branches are often swollen at nodes.
The leaves are usually opposite,persistent,often thick and fleshy,simple and exstipulate.

Inflorescence and flowers:
The flowers are mostly in axillary spikes, racemes or cymes.
The flowers are often showy bisexual or unisexual, actinomorphic or with a tendancy to zygomorphy(Dendropthe) and epigynous.They are usually bracteate and often with a pair of bracteoles.
The perianth is often biseriate with two similar di or tri merous whorls. The tepals are free or united into a tube which often splits down to one side.
The stamens are many.The anthers are dithecous. A pistillode is often present in the staminate flowers and a staminode in female flowers.The gynoecium is bi or tri carpellary and syncarpous
The fruit is a berry or drupe.
Pollination is by insects or small birds.
The fruit is covered by the fleshy outer receptacle which has an outer viscid layer.This adheres to the beak of the birds. When the bird rubs the beak to get rid of the seeds they adhere to the branches of the new host where they germinate and soon develop haustoria which penetrates the tissues.
Examples:
Dendropthe falcata
Viscum album

LILIACEAE

Gloriosa


Allium cepa


Asparagus


Scila hyacinthina


Cholrophytum


Iphiginia


Tulip

FAMILY OF THE WEEK:LILIACEAE
A large family widely distributed in most parts of the world. In India there are 35 genera and 189 species majority of them occurring chiefly in the Himalayas.
Vegetative characters:
They are mostly perennial herbs persisting by means of a sympodial rhizome or by a bulb. Sometimes as in Asparagus they are annual herbs.
Yucca, Dracaena and Aloe are shrubby or treelike with a perennial aerial stem growing in thickness by successive rings of meristem. The species of Smilax and Heterosmilax are woody climbers with often prickly stem. They climb with the help of stipular tendrils which arise from the leaf sheath.
The species of Asparagus are rhizomatous plants with herbaceous or woody erect straggling or climbing stems. The leaves are reduced to tiny scales and the ultimate branches become needle like or flattened. These cladodes take up the function of the leaves. Gloriosa is a perennial tuberous herb with a climbing stem. The climbing is affected by the leaf tip which elongates to form a spiral.
The leaves are basal(Allium,Lilium) or cauline. They are usually alternate, rarely opposite(Gloriosa) or whorled. They vary in shape from linear to broadly ovate. They are fleshy in Aloe with a large water storing tissue. The venation is parallel but in Smilax the leaves are net-veined. In Asparagus the leaves are reduced to minute scales.
Inflorescence and flowers:
Flowers are born in simple or branched racemes. They form apparent umbel in Alium subtended by spathe like bracts. In Yucca The inflorescence is a huge terminal panicle. Sometimes the flowers are solitary terminal as in Lilium.
The flowers are often showy,bisexual, actinomorphic or slightly zygomorphic, usually trimerous and hypogynous.
The perianth is of six tepals arranged in two whorls.They are free or united. The perianth segments are usually petalloid and the two whorls are generally undifferentiated.
Androecium is usually of six stamens in two whorls.The filaments are free or variably connate. The anthers are basifixed, dithecous,introrse or extrorse.
The gynoecium is tricarpellary and syncarpous with a superior and trilocular ovary. The style is usually one with three distinct stigmas. Usually the ovary has three septal nectaries.
The fruit is usually a loculicidal or septicidal capsule or sometimes a berry as in Smilax and polygonatum.
Pollination: Showy fragrant flowers and nectaries are for insect pollination.
Examples:
The family provides several food,drug and fibre plants and many genera are important as ornamentals.
Allium cepa(Onion.Piyaz,kanda)
Allium sativum(Garlic, Lasun)
Asparagus officinalis (Garden asparagus) Fleshy shoots as vegetables.
Asparagus plumosus : several varieties cultivated as ornamentals.
Aloe vera (Korphad)
Scilla hyacinthina (South Indian Squill)
Smilax
Gloriosa superba (Glory lily,Kal-lawi)
Iphigenia indica :Flowers yield red dye.
Lilium(Lily) They rank high among bulbous ornamentals.L.giganteum;L.candidum.
Yucca Tulipa (Tulip)
Dracaena.

LAMIACEAE(LABIATAE)

Ocimum sanctum



Pogostemon deccanensis


Leea (Dinda)

FAMILY OF THE WEEK : LAMIACEAE (LABIATAE) MINT FAMILY
Rather large family.The Mediterranean region is the chief centre of distribution. In India 64 genera and 380 species occurring chiefly in dry areas and moderate altitudes. The two chief centres of distribution are south India and North western India.The familiar examples include Mentha, Holy basil and Sage.
Vegetative characters:
Mostly annual or perennial herbs, sometimes shrubs or rarely small trees.
The stems of herbaceous species are often quadrangular.
The leaves are opposite bor sometimes whorled, exstipulate,simple and the blade is from entire to finely multisect as in Salvia.
They are abundantly loaded with epidermal glands secreting volatile aromatic oils which impart characteristic odour.
Inflorescence and flowers:
The inflorescence is usually a dichasial cyme which often becomes cincinal in its later branching.These cymes occur at the leaf axil and often form a whorl of flowers at each node. This type of inflorescence is often called as verticillaster. Each flower is subtendede by a bract and a pair of bracteoles.
The flowers are perfect, hermaphrodite,zygomorphic and hypogynous.
The calyx is persistent and composed of five sepals which show various degree of union.
The corolla is gamopetallous and is differentiated into a tube and a limb. The tube is straight or bent and often widens upwards. The limb is usually two lipped.
The stamens are usually four,didynamous and are inserted on the corolla tube.
The gynoecium is bicarpellary and syncarpous. The ovary is superior,deeply four lobed,bilocular.The stigma is usually bifid.
A hypogynous disc is present at the base of the ovary. It is usually four-lobed.
The fruit is of four one seeded nutlets enclosed by the persistent calyx.
Pollination: The bright coloured flowers with nectar secreting disc are adapted for insect pollination. They are mostly visited by moths and butterflies.
Examples:The Lamiaceae are chiefly valuable as a source of volatile essential oils which are used for flavouring, for perfumery and for medicine and some garden ornamentals.
Ocimum (Basil)Several species yield oils.
Ocimum sanctum(Holy Basil, Tulsi)
Ocimum americanum Ocimum canum(Ran tulas)
Ocimum grattissium(Shrubby basil)
Ocimum basilicum(Sweet basil, Kali Tulas)
Ocimum kilimandscharicum is a rich source of camphor.
Mentha. Several species are useful for essential oils.
Mentha pepperminta:Source of peppermint oil.
Mentha pulegium
Lavandula :source of lavender oil.
Pogostemon Plectranthus Thymus Salvia
Coleus : Herbs with variously coloured, variegated and showy foliage.
Colebrookea oppositifolia
Origanum majorana (Maarwa)
Leonotis
Leea