Ferns of the Organ Mountains
Outline:
1. What are ferns?
-features; life cycle; special characteristics like
sori and gametophytes; desert adaptations
2. The Organ Mountains
-a little geography and geology, and some of the
habitats where you’ll find ferns.
3. Ferns in the Organs
-some of the common ferns found in the Organ Mts.
and where you might see them.
1: What are ferns?
Ferns are plants that:
-have vascular tissue (unlike mosses and liverworts)
-have “true” leaves (unlike clubmosses,
spikemosses, and horsetails)
-do not have seeds (unlike conifers and flowering
plants)
-do not have flowers (unlike flowering plants)
They reproduce via spores, produced in structures called
sori (which we’ll see in a moment). These spores grow into
a structure called a gametophyte; it’s called that because
it produces gametes (sperm and eggs). When those
gametes join, you get a new sporophyte (what we call the
typical leafy plant that produced the spores, to
distinguish it from the gametophyte).
Fern life cycle
haploid (n)
spores
gametophyte
(meiosis)
sori on leaves
sperm eggs
(fertilization)
diploid (2n)
sporophyte
Let’s not worry about diploid vs. haploid much for the moment.
The general idea is that a sporophyte, what you’re used to
thinking of as a fern, makes spores. The spores then grow into a
gametophyte, which makes sperm and eggs. The sperm and eggs
then join to form a new sporophyte.
Sporophyte
Sori
R. Moran
Gametophytes
Sori: why are they important?
Sori have a lot of variability between groups, and are
often very distinctive. So we use them a lot for
identification.
Gametophytes: why are they important?
Ferns are a bit
like amphibians.
Digression: frogs...
Adult frogs in desert areas fall into two categories:
some, like spadefoot toads (left) can become dormant
in dry periods; others, like leopard frogs (right) need
constant water.
Frogs, continued...
But, whether the
frog is a spadefoot or
a leopard frog, its
tadpoles need
constant water.
Sporophytes are like adult frogs
Though all fern sporophytes need water for active growth,
like frogs they fall into two categories: those that live in
dry microhabitats and become dormant during dry periods,
and those that can only survive in microhabitats that
provide constant water.
Gametophytes are like tadpoles
R. Moran
But, whether the sporophyte
can survive drying or not,
the gametophyte can’t.
It needs constant water to
survive and a film of water
for fertilization; if it dries, it
dies.
So for desert ferns, the
gametophyte is often the
limiting step.
Gametophytes 2
So how do ferns deal with the limitations of droughtintolerant gametophytes? Two main ways:
1. Have the gametophyte around for as short a time as
possible. While ferns from wet areas might have their
gametophytes sitting around for 3 months or more,
desert ferns can go from spore to new sporophyte in as
little as two weeks!
2. Give up on sex! If a fern can skip that pesky
sperm/egg part, it can get to the sporophyte stage
more quickly and doesn’t need a film of water for
fertilization.
2. The Organ
Moutains
This is a NASA satellite image
The Organ Mountains
The figure at right
shows a simplified
view of the geology
of the Organs.
Purple is rhyolite, a
volcanic, greyish rock.
Blue is limestone, a
sedimentary rock that
forms in oceans.
Red is quartzmonzonite, a kind of
granite.
Different rocks,
different ferns!
The Needles: granite.
The best fern habitats in the granite part of the mountains
are rocky, relatively moist slopes with occasional seeps
that have water most of the year.
Bishop’s Cap: limestone.
Bishop’s Cap has dry, gravelly slopes and ravines;
a few ferns can survive on the slopes, others are
limited to sheltered microhabitats.
La Cueva & Dripping Springs: rhyolite.
The rhyolite areas offer steep, narrow canyons. These
provide areas of constant water that some ferns need
and a wide range of good rocky outcrops and slopes.
3. Ferns in the Organ Mts.
Aspleniaceae:
? Asplenium palmeri ?
Asplenium resiliens
Asplenium trichomanes
Dennstaedtiaceae:
Pteridium aquilinum
Dryopteridaceae:
Cystopteris reevesiana
Dryopteris filix-mas
Phanerophlebia auriculata
Woodsia cochisensis
Woodsia neomexicana
Woodsia phillipsii
Woosdia plummerae
Pteridaceae:
Adiantum capillus-veneris
Argyrochosma limitanea
Astrolepis cochisensis
Astrolepis integerrima
Pteridaceae, cont.:
Astrolepis sinuata
Astrolepis windhamii
Bommeria hispida
Cheilanthes bonariensis
Cheilanthes eatonii
Cheilanthes feei
Cheilanthes fendleri
Cheilanthes lindheimeri
Cheilanthes tomentosa
Cheilanthes villosa
Cheilanthes wootonii
Cheilanthes wrightii
? Cheilanthes yavapensis ?
? Notholaena grayi ?
Notholaena standleyi
Pellaea atropurpurea
Pellaea intermedia
Pellaea truncata
Pellaea wrightiana
The short version: 31 ferns definitely in the Organs, 3 might be;
4 families of ferns in the Organs, Pteridaceae (brake family) with
the most species.
Ferns and geology.
Aspleniaceae:
Asplenium resiliens
Asplenium trichomanes
Dennstaedtiaceae:
Pteridium aquilinum
Dryopteridaceae:
Cystopteris reevesiana
Dryopteris filix-mas
Phanerophlebia auriculata
Woodsia cochisensis
Woodsia neomexicana
Woodsia phillipsii
Woosdia plummerae
Pteridaceae:
Adiantum capillus-veneris
Argyrochosma limitanea
Astrolepis cochisensis
Astrolepis integerrima
Pteridaceae, cont.:
Astrolepis sinuata
Astrolepis windhamii
Bommeria hispida
Cheilanthes bonariensis
Cheilanthes eatonii
Cheilanthes feei
Cheilanthes fendleri
Cheilanthes lindheimeri
Cheilanthes tomentosa
Cheilanthes villosa
Cheilanthes wootonii
Cheilanthes wrightii
Notholaena standleyi
Pellaea atropurpurea
Pellaea intermedia
Pellaea truncata
Pellaea wrightiana
Purple: occurs on rhyolite; Orange: occurs on rhyolite and granite;
Blue: occurs on limestone; Green: occurs on limestone and
rhyolite/granite.
Ferns and geology, cont..
Aspleniaceae:
Asplenium resiliens
Asplenium trichomanes
Dennstaedtiaceae:
Pteridium aquilinum
Dryopteridaceae:
Cystopteris reevesiana
Dryopteris filix-mas
Phanerophlebia auriculata
Woodsia cochisensis
Woodsia neomexicana
Woodsia phillipsii
Woosdia plummerae
Pteridaceae:
Adiantum capillus-veneris
Argyrochosma limitanea
Astrolepis cochisensis
Astrolepis integerrima
Pteridaceae, cont.:
Astrolepis sinuata
Astrolepis windhamii
Bommeria hispida
Cheilanthes bonariensis
Cheilanthes eatonii
Cheilanthes feei
Cheilanthes fendleri
Cheilanthes lindheimeri
Cheilanthes tomentosa
Cheilanthes villosa
Cheilanthes wootonii
Cheilanthes wrightii
Notholaena standleyi
Pellaea atropurpurea
Pellaea intermedia
Pellaea truncata
Pellaea wrightiana
Purple: occurs on rhyolite; Orange: occurs on rhyolite
and granite; Blue: occurs on limestone; Green: occurs on
limestone and rhyolite/granite.
Notice: the
rhyolite areas
have the most
ferns, and seven
of them don’t
occur in other
parts; no ferns
occur only on
granite but a lot
occur on rhyolite
and granite; four
ferns occur only
on limestone.
Fern families
So, I told you sori are useful in identification, and here’s
the proof... we’ll look at the three families you’re likely to
see in the Organ Mts.
Aspleniaceae (spleenwort family)
In this family,
the sori are oval
or linear, with
a flap (called the
indusium) along
one side.
These ferns
require nearly
constant moisture.
Dryopteridaceae (shield fern family)
In this family, the
sori are round, with
that flap (indusium),
forming a shield or
cup-like structure.
These ferns also
require nearly
constant moisture.
Pteridaceae (brake family)
In this family, the
sori form lines along
the edges of the
leaflets, protected
by the edge of the
leaf or unprotected.
These are the true
arid-dwelling ferns,
living in the driest
habitats.
Pteridaceae, cont.
Aspleniaceae:
Asplenium resiliens
Asplenium trichomanes
Dennstaedtiaceae:
Pteridium aquilinum
Dryopteridaceae:
Cystopteris reevesiana
Dryopteris filix-mas
Phanerophlebia auriculata
Woodsia cochisensis
Woodsia neomexicana
Woodsia phillipsii
Woosdia plummerae
Pteridaceae:
Adiantum capillus-veneris
Argyrochosma limitanea
Astrolepis cochisensis
Astrolepis integerrima
Pteridaceae, cont.:
Astrolepis sinuata
Astrolepis windhamii
Bommeria hispida
Cheilanthes bonariensis
Cheilanthes eatonii
Cheilanthes feei
Cheilanthes fendleri
Cheilanthes lindheimeri
Cheilanthes tomentosa
Cheilanthes villosa
Cheilanthes wootonii
Cheilanthes wrightii
Notholaena standleyi
Pellaea atropurpurea
Pellaea intermedia
Pellaea truncata
Pellaea wrightiana
Just a reminder:
most ferns in the
Organ Mts. are in
Pteridaceae; no
surprise given
that it’s the most
drought-tolerant
of the families.
So, now I’ll go through the three major parts of the
Organs and show you some ferns you’d see there.
Let’s start with Bishop’s Cap (A Mt. is similar).
Astrolepis cochisensis (Cochise cloak fern): most
common fern on dry limestone.
Astrolepis cochisensis (Cochise cloak fern): most
common fern on dry limestone.
Astrolepis integerrima (hybrid cloak fern): also on
dry limestone
Cheilanthes feei (Fee’s lip fern): under overhangs,
locally moist limestone.
Cheilanthes feei (Fee’s lip fern): under overhangs,
locally moist limestone.
In the granite portion of the mountains, you can see
a number of ferns at Aguirre Spring
Cheilanthes fendleri (Fendler’s lip fern): common in
cracks in granite
Cheilanthes fendleri (Fendler’s lip fern): common in
cracks in granite
Cheilanthes fendleri (Fendler’s lip fern): common in
cracks in granite
Cheilanthes eatonii (Eaton’s lip fern): usually
under or between granite boulders
Cheilanthes eatonii (Eaton’s lip fern): usually
under or between granite boulders
Pellaea truncata (spiny cliff-brake): amid
granite boulders, lower elevations
Woodsia neomexicana (New Mexican cliff fern): in
moist soil or under granite boulders
Woodsia phillipsii (Phillips’ cliff fern): in moist
soil or under granite boulders
And, last, let’s consider some of the ferns you’d near at
Dripping Springs; we’ll see many of these on the next
field trip!
Some will be the
same as what we’d
see at Aguirre, but
others won’t.
Notholaena standleyi (star cloak fern): in cracks
in exposed rhyolite
Cheilanthes bonariensis (golden lipfern): occurs in
moist soil near pools and seeps
Cheilanthes bonariensis (golden lipfern): occurs in
moist soil near pools and seeps
Pellaea atropurpurea (purple cliffbrake): occurs in
rocky soil under oaks
Pellaea atropurpurea (purple cliffbrake): occurs in
rocky soil under oaks
Pellaea wrightiana (Wright’s cliff-brake): found
in cracks in exposed rhyolite & among boulders
Pellaea wrightiana (Wright’s cliff-brake): found
in cracks in exposed rhyolite & among boulders
Astrolepis sinuata (wavy cloakfern): occurs
in rocky soil on moist slopes
Phanerophlebia auriculata (eared veinfern): occurs
under boulders in the moist bottoms of steep canyons
Asplenium resiliens (maidenhair spleenwort): occurs
on moist rock in seeps
Asplenium trichomanes (maidenhair spleenwort): occurs
on moist rock in seeps
Asplenium trichomanes (maidenhair spleenwort): occurs
on moist rock in seeps
Shameless self-promotion:
Want to see more pictures of ferns and other local
plants? Well, I have a website:
www.polyploid.net
or:
www.newmexicoflora.com