Division : Filicophyta
Class : Leptosporangiopsida
Order : Filicales
Family : Polypodiaceae
Sub-family : pteridioideae
Common Indian Species
P. vittata, P. cretica, P. biaurita, P. ensiformis,
P. adscensionis, P. wallichiana etc...
Occurrence of distribution
lCosmopolitan fern being distributed in almost
lIt prefers tropical and subtropical climates.
lPlants usually grow in well drained places or in
crevices of rocks.
lThey are very common along the slopes of hills
and can be seen at 1200 metre above sea level.
lThere are aboubt 250-280 species reported for
Morphology of Sporophyte
lSporophyte is differentiated into root, stem and
lPrimary root is soon replaced by the
adventitious roots. Roots are slender, black, wiry
and arise from ventral side of rhizome or all over
lStem is rhizomatous, underground, branched,
perennial and covered by brown scales. Some
species have persistant leaf bases on rhizome.
lLeaves- Macrophyllous, unipinnate or imparipinnate
(P. vittata) or Bipinnate (P. biaurita). Arise
acropetally on the rhizome. Develped leaves are
lPetiole base is covered with brown scales and
sometimes with ramenta
lRachis has several sessile, lanceolate leaflets
arranged in pairs except the terminal one.
lLeaflet is rough ,has a midrib from which the lateral
veins with dichotomous branching arise. Venation is
open dichotomous venation.
lYounger leaves shows circinate vernation.
Anatomy of sporophyte
1) Anatomy of Rhizome
lRhizome is differentiated in to epidermis,cortex
lEpidermis-single layered with quadrangular
cells,covered by cuticle.
lCortex-multi layered,differentiated in to
Sclerenchymatous hypodermis and inner broad
parenchymatous region. parenchymatous region
has root and leaf traces.
lStele-In P. vittata it is dictyostele with a ring of
vascular strand (meristele).
lMeristele is embedded in the parenchymatous
lEach meristele is elliptical with single layered
endodermis having casparian strips in its radial
l1-2 layered thin walled pericycle is present below
the epidermis and surrounding the phloem.
lPhloem has only sieve cells and phloem
parenchyma. It completely surrounds the xylem.
lXylem is present at the centre of meristele. It
shows central protoxylem surrounded on
either side by metaxylem.
lIt consists of tracheids and xylem parenchyma.
2) Anatomy of Petiole or Rachis
lIt is differentiated in to epidermis,ground
tissue and vascular bundle.
lEpidermis-single layered with narrow
quadrangular cells coverd by thick cuticle.
lSome epidermal cells give rise uniseriate
bicellular hairs called as ramenta.
lGround tissue-It has multilayered
sclerenchymatous hypodermis followed by
parenchymatous tissue in which the vascular
bundle is embedded.
lVascular bundle-It is 'V' or 'U' shaped.
lIt resembles meristele and has single layered
endodermis with casparian strips.
lPericycle is 1 or 2 layered and
lXylem is at the centre with mesarch condition
surrounded by phloem.
3) Anatomy of leaflet
lIt has epidermis, mesophyll and vascular bundle.
lEpidermis - single layered present on both upper
and lower surfaces. It has stomata only on the
lower epidermis(Hypostomatous condition).
lMesophyll - either homogenous or differentiated in
to upper pallisade and lower spongy with broader
lHypodermal region of mid rib has
sclerenchymatous strips in both abaxial and adaxial
lMid rib has single concentric, amphicribal
vascular bundles surrounded by single
layered pericycle and endodermis.
lVascular strands are embedded in the
4) Anatomy of Root
lIt is differentiated in to epidermis ,cortex and
lEpidermi-single layered with thin walled cells.A
few cells form root hairs.
lCortex -multilayered and differentiated in to
parenchymatous outer cortex
,sclerenchymatous inner cortex and single
layered endodermis with casparian thickenings.
lStele -it has single layered thin walled
pericycle,central plate like exarch and diarch
xylem surrounded on either side by phloem.