Mottled Leaves - Revision history

P>Pacsoa at 17:57, 9 August 2024

2024-08-09T17:57:57Z

← Older revision		Revision as of 17:57, 9 August 2024
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	temperature variations or wind. A few have silvery-lepidote		temperature variations or wind. A few have silvery-lepidote
	undersides to the leaves, such as		undersides to the leaves, such as
	''[[Kerriodoxa elegans]]''		''[Kerriodoxa elegans]''
	from Thailand or ''[[Mauritiella]]'' and		from Thailand or ''[Mauritiella]'' and
	''[[Astrocaryum]]'' from the Neotropics. Most palms are of		''[Astrocaryum]'' from the Neotropics. Most palms are of
	course rainforest plants and don't need to be glaucous so		course rainforest plants and don't need to be glaucous so
	have mid green leaves which are suited to catching as much		have mid green leaves which are suited to catching as much
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	many of which lose the mottling as they mature, but some		many of which lose the mottling as they mature, but some
	retain it into adulthood, like		retain it into adulthood, like
	''[[Pinanga densiflora]]''		''[Pinanga densiflora]''
	or ''[[Pinanga maculata]]''.		or '';Pinanga maculata]''.

	Most mottled palms are shrubs of the rainforest understory		Most mottled palms are shrubs of the rainforest understory
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	for those that have developed mottling in this fact.		for those that have developed mottling in this fact.

	Apart from a species of ''[[Geonoma]]'' mottling of understory palm		Apart from a species of ''[Geonoma]'' mottling of understory palm
	leaves never became widespread in the Americas, despite there		leaves never became widespread in the Americas, despite there
	being a vast array of shrubby palms there in an even wider		being a vast array of shrubby palms there in an even wider
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	[https://images.google.com/images?q=Mottled+leaves+Palms&hl=en&btnG=Google+Search GoogleImages],		[https://images.google.com/images?q=Mottled+leaves+Palms&hl=en&btnG=Google+Search GoogleImages],
	<p>		<p>
	[[Category:~~Palm_Articles~~\|~~Mottled_Leaves~~]]		[[Category:Mottled\|Leaves]]
	[[Category:Palm\|Mottled_Leaves]]		[[Category:Palm\|Mottled_Leaves]]

Pacsoa at 13:28, 9 August 2024

2024-08-09T13:28:20Z

← Older revision		Revision as of 13:28, 9 August 2024
Line 8:		Line 8:
	temperature variations or wind. A few have silvery-lepidote		temperature variations or wind. A few have silvery-lepidote
	undersides to the leaves, such as		undersides to the leaves, such as
	''[Kerriodoxa elegans]''		''[[Kerriodoxa elegans]]''
	from Thailand or ''[Mauritiella]'' and		from Thailand or ''[[Mauritiella]]'' and
	''[Astrocaryum]'' from the Neotropics. Most palms are of		''[[Astrocaryum]]'' from the Neotropics. Most palms are of
	course rainforest plants and don't need to be glaucous so		course rainforest plants and don't need to be glaucous so
	have mid green leaves which are suited to catching as much		have mid green leaves which are suited to catching as much
Line 39:		Line 39:
	many of which lose the mottling as they mature, but some		many of which lose the mottling as they mature, but some
	retain it into adulthood, like		retain it into adulthood, like
	''[Pinanga densiflora]''		''[[Pinanga densiflora]]''
	or '';Pinanga maculata]''.		or ''[[Pinanga maculata]]''.

	Most mottled palms are shrubs of the rainforest understory		Most mottled palms are shrubs of the rainforest understory
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	for those that have developed mottling in this fact.		for those that have developed mottling in this fact.

	Apart from a species of ''[Geonoma]'' mottling of understory palm		Apart from a species of ''[[Geonoma]]'' mottling of understory palm
	leaves never became widespread in the Americas, despite there		leaves never became widespread in the Americas, despite there
	being a vast array of shrubby palms there in an even wider		being a vast array of shrubby palms there in an even wider
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	[https://images.google.com/images?q=Mottled+leaves+Palms&hl=en&btnG=Google+Search GoogleImages],		[https://images.google.com/images?q=Mottled+leaves+Palms&hl=en&btnG=Google+Search GoogleImages],
	<p>		<p>
	[[Category:~~Mottled~~\|~~Leaves~~]]		[[Category:Palm_Articles\|Mottled_Leaves]]
	[[Category:Palm\|Mottled_Leaves]]		[[Category:Palm\|Mottled_Leaves]]

Pacsoa: 1 revision imported

2024-08-09T13:22:02Z

1 revision imported

New page

{{PalmSpeciesHeader}}
__NOTOC__
===Mottled Leaves===
Palms are normally thought of as being relatively colourless
and plain in terms of their leaves. The majority of them are
mid to dark green with some developing a waxy glaucousness
where the leaf has to be protected from dryness, excessive
temperature variations or wind. A few have silvery-lepidote
undersides to the leaves, such as
''[Kerriodoxa elegans]''
from Thailand or ''[Mauritiella]'' and
''[Astrocaryum]'' from the Neotropics. Most palms are of
course rainforest plants and don't need to be glaucous so
have mid green leaves which are suited to catching as much
light as possible.

There are, however, a number of species with curious and
very attractively mottled leaves. These plants are often
termed variegated, and in reality the mottling is a form of
variegation, but the term conjures up visions of the mutant
striped foliage of plants which have an inability to produce
chlorophyll evenly in the tissues as they form in the
meristem. There are palms with such variegation, but these
are abnormal within the population of that species and
normally experience such disadvantages, due to their lack of
normal vigor, that they do not persist in the wild. Such
variegated palms are therefore rare and can only be
maintained under cultivation.

Of the mottled palms, the variegation is a quite different
form. Rather than occurring in streaks which are really
chlorophyll-free tissues that form as the new growth is
"extruded" from the growing point, and are therefore parallel
to the venation of the plant, mottled palm leaves show a very
organised patterning of darker tissue areas surrounded by
lighter tissues, or in some, by patterns of surface texture
which refract the light, giving a silvery, almost metallic
appearance. The feature is most common in juvenile plants,
many of which lose the mottling as they mature, but some
retain it into adulthood, like
''[Pinanga densiflora]''
or '';Pinanga maculata]''.

Most mottled palms are shrubs of the rainforest understory
where they spend their entire lives in the humid and dark
confines under conditions of relatively intense space
competition, having tree seedlings, other palm seedlings and
specialised ground-living plants to deal with. They also have
to deal with grazing animals such as deer, wild pigs, land
snails and insects In some areas of Malaysia the forest fauna
contains wild cattle, tapirs and primates, which can be very
destructive. Life for the tiny understory palm is not as easy
as it looks from a first glance. There may be an explanation
for those that have developed mottling in this fact.

Apart from a species of ''[Geonoma]'' mottling of understory palm
leaves never became widespread in the Americas, despite there
being a vast array of shrubby palms there in an even wider
array of habitats. For some reason it has not been part of
their evolutionary development. Whether this means that the
pressures that encourage the development of mottled leaves
elsewhere are not present or is a reflection of the genetic
background of the plants is hard to say, possibly it is a
combination of both factors.

It is in the South-East Asian tropics where leaf mottling
has attained such heights of development as to be almost
normal amongst at least one genus, ''Pinanga''. This genus has
about 120 known species of very specialised plants, some of
which are so unlike the generic "norm" that their flowers
have to be seen to place them. Most are clump-forming shrubs
with pinnate leaves that are variously divided into groups of
leaflets rather than being perfectly freepinnate. Many have
completely undivided leaves or leaves with a mere two or
three major leaflet assemblages along the rachis.

A few are tall trees which compete in the lower canopy level
but many are tiny plants of the leaf litter and ground
herbage zone. It is amongst these latter that mottling is
conspicuous, or rather not conspicuous at all for some are of
such unplant-like colours and patterns that they are very
well hidden and are difficult to see.
''P. veitchii''
is such a palm, the leaves are a brownish colour with the
appearance of being dry. There is a certain degree of
metallic surface texture which gives the leaf a somewhat
velvet-like cast and the mottling breaks up the outline of
the leaf very effectively.

It is not just ''Pinanga'' that does this, although this
genus is the mottle-specialist, because a recently discovered
''Licuala''
( ''L. mapu'')
has been found with mottled leaves.
The mottling is quite unlike that of ''Pinanga'' however,
and seems to make the plant more conspicuous.

''Licuala'' is exceedingly diverse in SouthEast Asia. With
over 108 species, most are in Malaysis, but a secondary area
of diversity exists in New Guinea. Borneo seems to have the
most interesting array of ''Licuala'' species, some of
which are considered to be sensational ornamental plants and
are now experiencing quite mercenary collecting at the hands
of commercial collectors. Some of these highly attractive
species occur in very limited populations and have to face
habitat loss as well. They probably grow slowly in the wild
and have considerable competition to deal with, so excessive
seed collecting may be detrimental to them in the long term.
Just why a palm would bother to evolve towards heavily
mottled leaves is something of a mystery. Perhaps it is a
defence against grazing herbivores who may not recognise the
leaf as being fresh, or do not notice its shape and associate
it with a tender palm. The same could be said of palms which
have brightly coloured new growth, perhaps in an attempt to
disguise the soft new growth as something inedible.
Why mottled palms tend to lose this feature as they mature
is also something of a mystery. Perhaps the mottling is no
longer needed as a defence against herbivores when the plant
is large enough to stand out of reach.

A mottling that is very similar to that of most
''Pinanga'' occurs in other plants. There are several
species of ''Pandanus'' in Malaysia and Indonesia, and at least
one in Madagascar which display this feature, but again, in
the case of the Asian pandans, the mottling is lost as the
plant matures. The mottling can be lost much sooner in
cultivated plants if nutrients and light management are not
carefully aftended to. In the botanic gardens we have found
that mottled ''Pinanga'' will become a rich, uniform dark
green if heavily fertilized and kept in bright light. Plants
of ''Pinanga disticha'' that were treated in such a way
lost their attractive patterning within weeks. Experiments
show that growing them in a nutritionally poor soil, such as
granite sand with a bit of peat and placed in relatively dark
areas will encourage a bright patterning. This poor
environment imitates the leached rainforest topsoils that the
plants have to deal with in the wild. The plants should be
fertilized occasionally with very dilute general fertilizer
and kept damp constantly. They will not grow robustly but
will make an attractive specimen plant.
</div>
</div>

===Contributed by: ===
Robert Tucker - Reproduced from '''''Palms & Cycads'''''
No. 37, Oct-Dec 1992.

===External Links:===
<p>[https://www.google.com/search?q=Mottled+leaves+Palms&num=10&sa=Google+Search Google],
[https://images.google.com/images?q=Mottled+leaves+Palms&hl=en&btnG=Google+Search GoogleImages],
<p>
[[Category:Mottled|Leaves]]
[[Category:Palm|Mottled_Leaves]]