Perfect Flower
A flower having both pistol and stamen (female and male respectively.)
Imperfect flower
A flower not having both pistol and Stamen (female and male) parts.
Complete Flower
A flower having all four whorls: Pistol (female), Stamen (male), Petals (collectively termed corolla), Sepals (collectively calyx).
Calyx
All of the small leaf like petals (sepals) on the layer below the petals of the flower.
Corolla
All of the petals on a flower.
Perianth
The Corolla and the Calyx together. (petals and protective sepals of flower)
Cotyledons
The first leafs a plant sprouts with from seed. The word behind the terms: monocot and Dicot.
Four types of Plant tissues
Vascular tissues (transport), Dermal tissues (protect), Meristem (young green growth :), Ground (Roots).