1. GEOPHYTES: A SPECIAL ADAPTATION
TO THE MANSOON SEASONALITY IN
WESTERN GHATS OF INDIA
Dr. S. P. GAIKWAD
Dept. of Botany,
Walchand College of Arts and Science,
Solapur-413 006 (MS), India
2. What is geophytes ?
Geophytes are plants with underground
perennial organs (bulbs, corms, tubers or
rhizomes) which enable them to survive in
unfavorable seasons.
They survive in period of environmental stress
such as summer drought or winter cold by dying
back to these underground storage organs.
Then they re-sprout new foliage in the next
favorable season.
Biogeographically, geophytes are widespread
around the World in many habitats, but they are
most diverse and abundant in the five
Mediterranean-climate ecosystem of the World
3. Geophytes in Western Ghats
The remarkable diversity of geophytes in the Northern Western Ghats can be
seen clearly in the herbaceous flora of lateritic plateaus where geophytes make
up 35% flora. A total 186 geophyte species have been recorded from northern
Western Ghats of India. They are belonging to 22 families of flowering plants
7
1 1 3 2 3 1 2
8
2 1 1
6
1 1 1 3 1 1 1 1
4
19
2 1
6
14 13
10
2
51
2 1 1
17
2 3 5 4
1 3
23
1
5
0
10
20
30
40
50
60
Araceae
Aponogeto…
Taccaceae
Colchicace…
Amaryllida…
Asparagac…
Anthericac…
Hypoxidac…
Orchidaceae
Commelin…
Eriocaulac…
Costaceae
Zingiberac…
Euphorbia…
Fabaceae
Begoniaceae
Cucurbitac…
Balsamina…
Asclepiada…
Apocynac…
Convolvul…
Apiaceae
Genus Species
5. Flowering phenology
Inflorescences produced during or to the end of the vegetative growing season.
However, several genera, mostly among monocotyledons (e.g.Amorphophallus,
Chlorophytum, Crinum, Curcuma, Drimia etc.)
A few genera like Brachystelma , Drimia etc. have been changed this pattern
of flowering. They flower in the summer (April-May), often without leaves.
The monsoon flowering species are generally synanthous i.e. flowers and
leaves developing simultaneously, whereas the summer flowering species are
often hysteranthus, i.e. flowers and leaves developing in different seasons.
Beside these above said pattern of flowering some geophytes like Euphorbia
fusiformis, E. fusiformisI var. khandalensis, Zeuxine gracilis and Z. longilabris
interestingly produce flowering in winter season.
A flowering pattern is constant for an every geophytes species.
8. Rarity and Endemism
About 101 geophyte taxa are endemic to the Western Ghats of India of
which 62 taxa are known only from Northern Western Ghats.
The genus Ceropegia has shown highest incidence of endemism with 20
endemic taxa. Curcuma has four endemic taxa. The genus Arisaema has
seven taxa and the incidence of endemism is high (85.71%). The genus
Habenaria has 14 (53.84%) endemic taxa out of 26
Critically
endangered
(CR)
11%
Endangere
d (EN)
8%
Vulnerable
(VU)
5%
Near
threatened
(NT)
8%Least
concern
(LC)
16%
Data
deficient
(DD)
5%
Not
evaluated
(NE)
47%
9. Life forms
Prostrate leaf act as water-
trapping umbrellas, reducing the
rate of water loss, and creating
favorable microclimates for
growth. According to Karen et al.
(1999) prostrate leaf create a
CO2 enriched environment below
the leaves. A moist environment
under leaf could encourage
activity of microorganism, which
in turn produce CO2. A CO2
enriched environment might
increase photosynthetic CO2
uptake.
10. Geophytes with grass
like leaves camouflage
with grasses, are more
difficult for herbivores to
recognize them and thus
protect the plants against
herbivory.
11. SEED BUOYANCY
Two types of seeds observed in geophytes
1. Seeds with a hard seed coat that gives the seeds a high capacity
of buoyancy for example Chlorophytum, Dipcadi, Drimia,
Iphigenia and Pancratium.
2. Second type of seeds are chlorophyllus probably lacking of
cork layer, non buoyant seeds e.g. Aponogeton bruggenii,
A. satarensis and Crinum viviparum var. viviparum.
12. During the last few decades, many habitats have taken over
by mining, windmills, widening of roads, construction of
townships and industries in the Northern Western Ghats.
Tourism has been growing in some of the scenic areas
putting severe pressure on fragile habitats. The management
of these pressures often threat to geophytes.
THREATS TO THE GEOPHYTES
