Types of flowersTypes of flowers

Part 2Part 2

According to corolla According to corolla SymmetrySymmetry

1. Sympetalous – when petals are joined partly or wholly

flower has connate petals. In such a corolla, one can distinguish different parts:

- the floral tube, - the throat, and - the lobes

2.Polypetalous2.Polypetalous

- The petals - The petals are not joinedare not joined

3. Actinomorphic (corolla)3. Actinomorphic (corolla) This flower of is actinomorphic (regular). This

means that the flower has a radial symmetry — it can be divided into two equal halves by two or more planes (5 here, shown by the yellow lines).

These are further classified as funnel shaped, tubular shaped and campanulate (narrower than tubular, a bell like

shape). Examples of families: Poppy family, cruciform and

rose family are few notable examples of actinomorphic morphology.

Crassula argentea

Here is another example of actinomorphic flower. In this case the floral parts are numerous. This example is a water lily (Nymphaea cultivar).

4. Zygomorphic 4. Zygomorphic

(irregular) flower(irregular) flower has a bilateral

symmetry — it can be divided in two equal halves by only one plane, as shown by the red line passing through this flower of Viola tricolor

Orchids have zygomorphic flowers. Here again, the flower can be cut into two symmetrical halves by only one plane, along the red line.

Perianth shape (usually applied to Perianth shape (usually applied to

corolla, but may be applied to calyx)corolla, but may be applied to calyx)

1.1. Rotate Rotate

- shallow - shallow and and relatively flat relatively flat or dish-or dish-shaped shaped

2. bilabiate2. bilabiate

(means "two-lipped") corolla is a zygomorphic, sympetalous corolla with the limb divided into two lips.

Lamium purpureum

3. Stellate3. Stellate= star-shaped  (this is not as commonly = star-shaped  (this is not as commonly

used as some other terms)used as some other terms)

Allium ursinum

4. 4. UrceolateUrceolate

= urn-shaped; somewhat flared out or inflated = urn-shaped; somewhat flared out or inflated and then narrowed at the opening and then narrowed at the opening

5. 5. CampanulateCampanulate

= bell-shaped, with = bell-shaped, with the segments gently the segments gently flaringflaring

6. 6. Tubular

= parts fused into a usually slender, uniform = parts fused into a usually slender, uniform tube, usually with the tube, usually with the free tips proportionately small and/or only slightly spreading

Cuphea ignea

free tips proportionately small

only slightly spreading

7. 7. FunnelformFunnelform = with parts fused into a tube that widens = with parts fused into a tube that widens

gradually from base to tipgradually from base to tip

8. 8. Salverform

= with a narrow with a narrow tube and an tube and an abruptly abruptly expanded, expanded, spreading spreading portion which is portion which is often called the often called the limb. limb. 

9. 9. Geniculate

= with an = with an "elbow" or "elbow" or bend where the bend where the perianth perianth changes changes direction direction suddenly suddenly

10. 10. Papilionaceous = from the French

word for "butterfly."  Applied to members of the Fabaceae in which the flower has one large petal, the banner or standard, two similar side petals called wings, and two folded or usually fused-together lower petals called the keel. 

11. 11. Spurred = with a spur-- a

hollow, usually nectar-bearing, backward or downward extension of a sepal or petal.  A flower may have more than one. Spurs may be short as in Viola (spur is at the top of the flower, behind the pedicel)

More than one More than one

12. 12. Ligulate or Ray

= zygomorphic and = zygomorphic and with all the petals pulled with all the petals pulled to one side into a flat, to one side into a flat, strap-like structure.  strap-like structure.  Typical of the sunflower Typical of the sunflower family, e.g., the "petals" family, e.g., the "petals" of a daisyof a daisy

Placentation Types Placentation Types

Placentation refers to the pattern of Placentation refers to the pattern of attachment of ovules within the attachment of ovules within the ovary.ovary.

1. Marginal1. Marginal ovules arranged along

the suture of a single, simple pistil (cross-section)

In monocarpous and apocarpous gynoecia (i.e. carpels distinct), the ovules are arranged along the suture of the carpel.

There is one locule per carpel, no septum (see definition on next slide). This is called marginal placentation. .

2. Axile 2. Axile a separate locule for each carpel and the a separate locule for each carpel and the

ovules attached to placentae in the middle ovules attached to placentae in the middle where the septa come together (cross-section) where the septa come together (cross-section)

In a syncarpous gynoecium, there can be one In a syncarpous gynoecium, there can be one or more locules, and various possible types of or more locules, and various possible types of placentation. This can be observed on cross- placentation. This can be observed on cross- and lateral sections of the ovary. and lateral sections of the ovary.

A A septumseptum (= "wall") is an interior wall which (= "wall") is an interior wall which separates the locules when two or more separates the locules when two or more chambers occur. The presence of septa is chambers occur. The presence of septa is characteristic of characteristic of axile placentation.axile placentation.

3. Parietal 3. Parietal

= ovules attached to the wall of a = ovules attached to the wall of a unilocular ovary (cross-section unilocular ovary (cross-section

there is no septum, so that the ovary is there is no septum, so that the ovary is unilocular. The ovules are borne on the unilocular. The ovules are borne on the inner surface of the ovary walls (or inner surface of the ovary walls (or extensions of the walls). extensions of the walls).

4. Free-central 4. Free-central

= ovules attached to a peg or stalk that = ovules attached to a peg or stalk that arises from the ovary floor but which arises from the ovary floor but which does not reach the roof; ovules usually does not reach the roof; ovules usually few to many (long-section) few to many (long-section)

5. Basal 5. Basal

= ovules attached to the floor of the ovary = ovules attached to the floor of the ovary (long-section) (long-section)

one or more ovules are attached to the bottom of the ovary. This situation is found for example in some Portulacaceae like Portulaca (photo on the left; the yellow arrow is pointing to the ovules) or in Talinum (close up on the right; the black arrow is pointing to the placenta). The ovary is unilocular.

6. 6. Apical placentationApical placentation: one or more : one or more ovules are attached at the top of the ovules are attached at the top of the ovary. The ovary is unilocular ovary. The ovary is unilocular

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