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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)


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