Flowers

• Flowers - The part of the shoot system specializing in sexual reproduction
• Basic Features of Flowers

  • A typical flower arises from the axil of the leaf.
  • A typical complete flower consists of four whorls.
  • Callyx – Outer whorl
  • Corolla – Middle Whorl
  • Essential Organs – Inner whorl
  • Stamen
  • Pistil
• Classification of Flower

  • Complete Flower
  • Incomplete Flower
  • Perfect Flower
  • Imperfect Flower
• COMPLETE FLOWER - A flower that has all the four essential floral parts: the sepal, petal, stamen and pistil
• INCOMPLETE FLOWER - A flower that lacks one or more of the four floral parts
• PERFECT FLOWER - A flower with both the stamen and pistil (may lack sepals and petals), also called bisexual flower
• IMPERFECT FLOWER

  • A flower that bears either the stamen or pistil.
  • The flower may be staminate or pistillate.
  • It is also called unisexual flower
• Size and Shape of Floral Parts

  • REGULAR FLOWER
  • IRREGULAR FLOWER
• REGULAR FLOWER - A flower in which the corolla is made up of similarly-shaped petals equally spaced and radiating from the center of the flower
• IRREGULAR FLOWER - A flower in which one or more members of at least one whorl are of a different form or size from others
• Types of Irregular Flowers

  • PAPILIONACEOUS
  • CAESALPINACEOUS
  • ORCHIDACEOUS
• PAPILIONACEOUS - The standard petal or banner is usually the largest and most striking
• PAPILIONACEOUS - The two wings or alae are lateral, and a keel is present
• PAPILIONACEOUS - Ex: batao and sitao flowers
• CAESALPINACEOUS - The standard petal is the smallest and innermost
• CAESALPINACEOUS - The two wings and two keels are almost the same in size and shape.
• CAESALPINACEOUS - Examples: fire tree (Delonix regia) and caballero (Caesalpinia pulcherrima)
• ORCHIDACEOUS - The flower has three petals; one is very much different in size and shape and is called the lip or labellum
• ORCHIDACEOUS - Examples: Palaenopsis, Cattleya, Dendrobium and sanggumay
• Position of the Ovary

  1. Hypogynous Flower
  2. Perigynous Flower
  3. Epigynous Flower
• Placentation

  1. Marginal
  2. Parietal
  3. Basal
  4. Axile
• MARGINAL - the ovules are attached to vertical rows or rows along the ovary wall.
• PARIETAL - in a compound pistil, the carpels are joined margin to margin and the placenta is situated on the ovary walls.
• BASAL - found in both simple and compound carpels with one locule in the ovary. The ovule is attached to the base of the ovary.
• AXILE - the ovules are attached to the middle of the ovary, where the septae of a compound pistil are joined.
• Fusion of Floral Parts

  1. Adnation
  2. Connation
• ADNATION - when unlike parts like the petals and sepals are fused
• CONNATION - when like parts are fused, as in the petals of Morning Glory
• INFLORESCENCE

  1. Spike
  2. Spadix
  3. Catkin
  4. Raceme
  5. Panicle
  6. Cyme
  7. Corymb
  8. Umbel
  9. Capitulum or Head
• SPIKE - elongated axis, flowers are sessile or without stalk. Example: black pepper (Peperomia pelucida)
• SPADIX - a spike with a fleshy axis, enclosed by a large, often brightly colored bract called spathe Example: Calla lily, Anthurium
• CATKIN - a spike with a long and pendulous axis; bears unisexual flowers only. Example: Acalypha hispida
• RACEME - elongated axis; bears a number of flowers which are all stalked, the lower flowers having longer stalks than the upper. Example: Cassia, Caesalpinia, Aloe
• PANICLE - main axis of the flower is branched and the lateral branches bear the stalked flower.

  • Example: rice, malunggay
• CYME - the main axis ends in a flower that opens before the flowers below or on its side open. The flowers may be with or without stalks. Example: baby’s breath, gladiolus
• CORYMB - the main axis is comparatively short. The lower flowers have longer stalks than the upper ones so that all flowers are brought more or less at the same level.

  • Example: caballero
• UMBEL - the primary axis is shortened and bears at its tip a group of flowers which have pedicels or more or less equal lengths, that they appear to spread out from a common point.

  • Example: sapinit (Lantara camara)
• CAPITULUM OR HEAD - the main axis is suppressed, becoming almost flat.

  •  The capitulum is composed of ray flowers along the margin and disk flowers crowded at the center of the flower.
  • Examples: sunflower, zinnia, gerbera and daisy
• CYATHIUM - consist of a cup-shaped involucre formed by fused heads

  • Example: Euphorbia
• VERTICILLASTER - with a cluster of sessile flowers in the axil of a leaf forming a false whorl at the node

  • Example: Coleus sp. (mayana)