PALYNOLOGY

1. POLLEN
APERTURE AND
SYMMETRY
Prepared by:
AIRA B. BELLEN
BSEd 3-P

2. POLLEN
APERTURE
A specially delimited region
of the pollen grain wall

5. FUNCTION
Primarily to serve as the site of
formation of a pollen tube exiting
from the pollen grain body
To allow volume changes of the
pollen grain with changes in water
content

6. HARMOMEGATHY
Allows the pollen grain
apertures to contract with
water loss, effectively sealing
the apertures via the
surrounding desiccation
resistant exine wall

7. POLLEN APERTURE
TYPE
Refers to the shape, number, position
and arrangement of the aperture of a
pollen grain
INAPERTURATE – pollen grains that lack
any recognizable aperture

8. GENERAL TYPES OF
APERTURE
1. COLPUS
an elongate aperture with a
length/width ratio of greater than
2:1
can be elliptic, oblong, or fusiform
in outline shape

9. GENERAL TYPES OF
APERTURE
2. PORUS
a circular to slightly elliptic
aperture with a length/width
ratio of less than 2:1

10. Triporate
Diporate
Pentoporate

11. GENERAL TYPES OF
APERTURE
3. PANTOPORATE
if pori occur
globally on the
pollen grain
surface

12. GENERAL TYPES OF
APERTURE
4. COLPORATE
shaped like a
colpus but has
a circular
region in the
center

13. GENERAL TYPES OF
APERTURE
5. ZONOAPERTURATE
/STEPHANOAPERTUR
ATE
pollen grains with
apertures occurring
in the equatorial
region

14. GENERAL TYPES OF
APERTURE
6. SULCUS
an elongate
aperture similar in
shape of a colpus
but either
centered at a pole
or more rarely,
parallel to the
equator

15. 7. ULCUS
a circular to
slightly elliptic
aperture similar in
shape to a porus
but occurring at
the pole
GENERAL TYPES OF
APERTURE

16. NUMBER OF APERTURES
Designated by appending the
prefix mono-, di-, tri-, tetra-,
penta-, hexa-, or poly- (more
than six) to the terms colpate
and porate

17. RARE & SPECIALIZED
APERTURE TYPES
Syncolpate
A pollen grain in which the colpi are joined
Trichotomosulcate
A three-branched aperture type
Spiraperturate
One or more apertures that are spirally
shaped.

18. POLLEN SYMMETRY
Generally either radially
symmetric or bilaterally
symmetric
Often incorporated or
assumed as a part of a shape
term

19. THANK YOU!