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Saturday 22 March 2008

BRASSICACEAE



Brassicaceae(Crusiferae) Mustard family
Annual, biennial or perennial herbs (Rarely under shrubs) with watery sap,(pungent juice)containing glucosinolates (mustard oils) and with myoresin cells.Hairs simple branches stellate or peltate.
Vegetative characters :
Leaves : alternate or in basal rosettes,radical or cauline,simple often dissected, rarely pinnately compound sometimes bearing bulbils in axils or leaf surface. Stipules absent.
Inflorescence : Typically racemose, corumbose raceme or flat topped corymb.
Flowers : ebracteate, rarely bracteate.bisexual actinomorphic rarely zygomorphic hypogynous.
Calyx : with 4 sepals free in two whorls.Sepals of lateral pair sometimes saccate at base green or petalloid.
Corolla : 4 petals cruciform, clawed.
Androecium : stamens 6 free tetradinamous(2 short 4 long) dehiscence longitudinal.Nectaries often at base of stamens, pollen grains tricolpate.
Gynoecium : Two united carpels (thus single pistil) syncarpous unilocular.Ovary superior.Gynophore distinct.Style 1 stigmas 2.
Fruit : Siliqua or silicula
Pollination : by insects and dispersal of seeds by wind.
Examples:
Family contributes to many food plants
Radish (Raphenous sativus)
Cabbage (Brassica oleracea var : capitata)
Cauliflower (Brassica oleracea var : botrytis)
Brussels sprouts
Turnip
Brassiaca campestris : seeds yield mustard oil used for cooking
Brassica nigra : black variety seeds used as condiment.
Common ornamentals include: stock(Mathiola) candy tuft(Iberis amara) alyssum(Alyssum) wall flower(Erysimum) and street alyssum(Lobularia)


Friday 14 March 2008

BOMBACACEAE


Pseudobombax ellipticum
Pseudobombax ellipticum











Pachira insignis
Bombax insignis
Pachira aquatica
Pachira aquatica
Bombax insignis














  












  





































Bombacaceae family was earlier included in Malvaceae family.
Even today some consider it as a subfamily of Malvaceae.
Habit: Tall tree with trunks and spreading branches.
Leaves: alternate simple or palmately compound stipulate
Flowers:showy bisexual,regular,hypogynous.
Calyx:Sepals 5,united,valvate.
Corolla:Patals 5,free,imbricate.
Androecium:stamens 5 to many,distinct or monadelphous,staminodes often,anthers 1-,2 or more celled.Pollen grains smooth.
Gynoecium:Carpels 2-5.Ovary superior.2-5 locular,placentation axile.
Fruit:capsule with a wooly or pithy pericarp.
Examples:
Bombax ceiba:Red silk cotton tree.Ceiba pentandra, Kapok:White silk cotton tree.
Chorisia speciosa.Delhi Sawar
Adansonia digitata:Baobab tree
Pseudobombax ellipticum: Shaving brush tree

Thursday 13 March 2008

BIGNONIACEAE



































































 
















BIGNONIACEAE (Trumpet Creeper Family)Mostly tropical.Around 40 species in India mostly in western and southern India and some in Himalayas.
Vegetative characters:Plant type trees,shrubs,woody climbers with tendrils or roots
Stem in climbers:abnormal secondary growth.
The Leaves :Opposite..rarely whorled or alternate
More frequently pinnately compound terminal leaflet often modified to tendril.
Stipules absent.
Flowers and Inflorescence:
Inflorescence:Dichasial cyme.
Bracts and bracteoles present.
Flowers :Showy,perfect,hermaphrodite,zygomorphic and hypogynous.
Calyx: gamosepalous,Campanulate.
Corolla :Gamopetalous,Bell or funnel shaped. % subequal lobes or bilabiate-Upper lip 2lobes;Lower lip 3lobes.
Stamens : 4 didynamous 5th reduced to staminode.Epipetalous.
Gynoecium :Bicarpellary and syncarpous with a superior ovarywhich is bilocular.
Style terminal,simple,and stigma is two lipped.
Nectar disc :cushion like or annular at the base of the ovary.
Fruit : Two valved:loculicidal or septicidal capsule fleshy and indehiscent in Kigelia.
Seeds : Compressed discoid.
Pollination :Showy flowers nectar:-insect pollination.
Seed dispersal :Seeds mostly winged:-Wind dispersal.


Examples.
Spathodia campanulata.Jacaranda mimosaefoliaKigellia pinnataHeterophragmaTabebuiaTecomaPyrostegiaCampsisRadermachera xylocarpa.

Monday 3 March 2008

ASTERACEAE





Chromolaena odorata [Eupatorium odoratum].

Tridax


ASTERACEAE( COMPOSITAE)
One of the largest families.The number of species all over the world around 13000...form more than 10% of the total number of species of flowering plants.
Vegetative characters:Annual or perennial.Mostly herbs,a small proportion shrubby, few are trees or woody climbers.Few species produce stem tubers or rhizomes, many species have a milky sap.Roots and stems commonly contain oil passages.
Leaves : alternate,rarely opposite or whorled,simple or pinnately or palmately lobed divided or compound and exstipulate.
Flowers and Inflorescence:The primary Inflorescence is Racemose head or capitulum.Primary heads often arranged into large inflorescence such as raceme corymb or compound heads.Each head is subtended by an involucre of green or membranous bracts. The number of flowers (florets) in a head varies from few to many but sometimes as in Echinops the heads are reduced to a single flower.The shape of the receptacle may vary from flat,concave,convex conelike.
The flowers are mostly bisexual,sometimes unisexual or neutral. In some all florets are alike while in some the central florets are actinomorphic while parietal are zygomorphic.
Flowers are pentamerous and epigynous.
The Calyx is sometimes altogether absent or represented by scarious five lobed rim at the top of the ovary.Usually it is represented by the pappus or hairs or bristles.
The corolla is of five fused petals.It may be tubular or ligulate
The stamens are five.The filaments are free but anthers are connate into a tube around the style.The stamens are usually included in the corolla tube.
The gynoecium is bicarpellary and syncarpous. The ovary is inferior and unilocular.The style is mostly bifid.
Fruits and seeds: The fruit is an achene often compressed and crowned by pappus of hairs plumes barbs or scales sometimes.The seeds are nonendospermic and with straight embryo.
Small flowers are attractive due to formation of heads and due to ray florets.Nectar is secreted by disc and collects in corolla tube. All of these favours insect pollination. Seeds are adapted for wind dispersal. Some fruits have hooks for animal distribution.
Examples:
The family provides some food,dye and oil yielding and medicinal plants,besides a large number of ornamental garden plants.
Lactuca sativa : cultivated as a salad crop.
Helianthus annus(Sunflower)सूर्यफुल
Carthamus tinctorius(Safflower) Important oil seed crop
Helianthus tuberosus: and Cyanara scoliamus :The roots are used as food
Tagetes minuta (Stinking Roger) and T.patula (French Marigold)Yield a strong aromatic essential oil.used as an antiseptic.
Tanacteum vulgare :(Tansy) essential oil used in rheumatism gout and in chronic ulcers
Taraxacum officinale:(Common Dandalion) drug Taraxacum from tuber useful as laxative and hepatic stimulant.
Spilanthus paniculata: flower heads are chewed to relieve toothache.
Calendula officinalis: The dried ligulate florets form the drug calendula used in sprains and bruises.
Chrysanthemum : A few species yield insecticide Pyrethrum.
The pollen of Ambrosia artemisifolia and Parthenium hysterophorus cause hay fever and skin allergies respectively.
Ornamentals:
Helianthus
Tagetus(
Marigold) T.erecta(African marigold) T. patula (French Marigold)
Dahlia Chrysanthemum Cosmos Zinnia Coreopsis Aster Gaillardia Dimorphotheca
Calendula(Pot Marigold)
Centaurea (Sweet sultan)