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Phoenix canariensis in the Wild
Reprinted
with permission from the April
1998 issue of Principes, Vol 42, No 2
Journal of the International Palm Society (Renamed as Palms in
1999)
© 1998 The International Palm Society, all rights reserved
CARLO MORICI
Departamento
de Biologta Vegetal (Boldnica), Universidad de La Laguna, Tenerife 38071,
Canary Islands, Spain
ABSTRACT
Phoenix
canariensis is one of the most grown and appreciated ornamental
trees of the world. Its native habitat, the Canary Islands, is renowned
for its richness in climatic diversity and its endemic flora. This Phoenix
apparently did not radiate, as did many other plants, but succeeded
in colonizing many different ecological niches. In each of these environments,
it grows associated with different ecological communities and often
shows an astonishing diversity of epiphytes on its fibrous trunks. The
wild populations suffered a dramatic decrease during the early centuries
of the Spanish colonization of the islands, which started at the end
of the 15th century. Today P canariensis is sparsely and un-evenly
distributed on all the seven islands and the conservation status is
different on each of them. The main threat seems to be hybridization
with P dactylifera.
RESUMEN
Phoenix
canariensis es uno de los ·rboles ornamentales m·s plantados y
apreciados del mundo. Su h·bitat de procedencia, las Islas Canarias,
es conocido por an riqueza en diversidad clim·tica y so flora endÈmica.
Esta especie de Phoenix aparentemente no sufriÛ radiaciÛn,
como pasÛ a muchas otras plantas, pero tuvo Èxito en colonizer muchos
nichos ecolÛgicos diferentes. En cada uno de estos medios, crece en
asociaciÛn con diferentes comunidades ecolÛgicas y a meliudo posee una
asombrosa diversidad de plantas epffÌtas en sus troncos fibrosos. Las
poblaciones naturales sufrieron una reducciÛn impresionante durante
los primeros siglos de la colonizaciÛn de las islas, a finales del siglo
XV. Hoy dÌa, P canariensis se encuentra distribuida de manera
esparcida y no uniformemente en todas las siete islas y el estado de
conservaciÛn es diferente en cada una de estas. El peligro principal
parece ser la hibridaciÛn con P dactylifera.
A
Softer Palm for a Softer Climate
 The origin of Phoenix
canariensis is not well documented. During the Tertiary, when many
tropical species that were occupying the Mediterranean area undertook a
huge and slow migration to the south because of the cooler weather, the
Canary Islands remained floristically isolated (Bramwell in Kunkel 1976)
as Northern Africa became a desert. A Phoenix has probably taken
part in this migration, but we do not know if the Phoenix that
migrated in the Tertiary was a P canariensis or a parent species
that afterwards evolved into the modern Canary palm.
These islands have by
far a more even climate than Northern Africa, with abundant humidity from
mist and richer soils. This suggests speciation from an ancestor similar
to Phoenix dactylifera (or perhaps P sylvestris), to the
less xeromorphic P. canariensis.
The Different Ecological Communities and Associations 
In present times Phoenix
canariensis is sparsely and unevenly distributed on all the islands
of the Canaries. It is very scarce on the two drier eastern islands of Lanzarote
and Fuerteventura and on the other islands it grows at lower altitudes in
the northern section of the islands, where it forms part of the bosque
termÛfilo, a Mediterranean subxeric (slightly dry) area, which has
now been mostly substituted by banana cultivation, hotels, and beautiful
gardens with ravenalas, scheffieras, and other exotics.
If the bosque termÛfilo
is almost gone (a good area survives in Los Silos, Tenerife), there are
some other ecological communities, known as "palmerales," that
have P canariensis as a dominant species, often associated with
Juniperus phoenicea and/or Dracaena draco (dragon tree).
Modern palmerales are usually very disturbed areas cultivated with
exotic crops, where the re-production of the palm is directly or indirectly
helped by man's presence. P canariensis may also contribute to
another ecological community called laurisilva. Laurisilva
is a sort of subtropical cloud forest endemic to the Canary Islands,
Madeira, and the Azores, mostly composed of trees of the Lauraceae family
and other "laurifolious" trees. It is unusual to see wild palms
growing in this environment but when it happens they take on a more "plumose"
appearance as in the population observed in the lower range of the forest
near Teno, Tenerife.
The palms are found
growing on a wide variety of soils, all of volcanic origin and usually fertile.
P canariensis has an extensive root system, which allows these
palms to explore the surrounding earth to find subterranean water even at
long distances. In the Canary Islands, Phoenix trees that grow
in subxeric areas show themselves to be resistant to temporary swamping
of the soil caused by sudden rains. Rivas-Martinez et al. (1993) explain
that other trees and shrubs, with typical root systems, which could act
as competitor species do not get established in those sites as they cannot
resist asphyxia caused by the waterlogged soil.
The wide distribution
of the palm on the island is reported and discussed by many authors and
some give specific locations of most palmerales (Bravo 1964, Montesinos-Barrera
1979, Barquin-Diez and Voggenreiter 1988, Bramwell and Bramwell, 1990, Anonymous
1992).
This is why the palmera
canaria is one of the most grown palm trees throughout the world. It
tolerates cold and warmth, drought and floods, shade and sun, and salt spray
as well as mountain climate.
Epiphytic
Life on P. canariensis
Those P canariensis
growing in humid environments, often host on their trunks many endemic epiphytic
plants, that add ornamental value to their already beautiful stems. I wish
to mention that the Canary Islands palm has the most fibrous and stout trunk
in its genus, and I suppose it is the only Phoenix species that
can host in its habitat such a spectacular mass of epiphytes on a single
specimen. The astonishing diversity of epiphytes that can be found growing
within the fibers of these spongy trunks is most unusual for nontropical
zones: Sonchus congestus (a yellow-flowered member of Asteraceae),
the majestic Sonchus acaulis, with rosettes up to 1 m in diameter,
the succulent Aeonium urbicum and A. ciliatum (Crassulaceae);
and the small creeping ferns Polypodium cambricum subsp. macaronesicum
and Davallia canariensis. All these plants show mechanisms
to withstand summer drought: the aeoniums are true succulents, the ferns
shed their leaves in summer, and the Asteraceae lose a large part of their
rosettes and wrap themselves inside their old dry leaves. Also other less
unusual nonendemic species may be found on the trunks, such as the annual
Fumaria officinalis, the tuberous Umbilicus horizontalis (Crassulaceae),
and the South African weedy bulb Oxalis pescaprae and some others.
In 1982 observations
were carried out (Haroun and Die 1982) on epiphytes that were growing on
Phoenix trunks of the historic palm avenue of Camino Largo, in
La Laguna (Tenerife), at 600 in a.s.l. The authors recorded 31 species,
but most of them were introduced exotics and some were nonepiphytic species
exceptionally found growing on palms, such as Erica sp. and Opuntia
sp. One interesting datum from this work is that 32.25% of these species
were zoochorous ones (animal-bome seed dispersal) and 67.75% anemochorous
(wind dispersed).
The
Different Islands
...
toda la isla era un jardÌn, toda poblada de palmas, porque de un lugar
que llaman Tamarasaite, quitamos m·s de sesenta mil palmitos i de otras
partes infinitas... Pedro Gomez Escudero
A description of the
island of Tenerife of the 16th century said: " . . . the northern side
of the island is completely covered by enchanting forests of palms and dragon
trees." In 1417, another writer, Pedro Gomez Escudero, said about Gran
Canaria: " . . . the whole island was a garden, all populated by palms,
because we took away from a place they call Tamarasaite more than sixty
thousand palm trees (cited in PadrÛn 1978).
In 1997 Tamarasaite
is called Tamaraceite and is a peripheral part of the city of Las Palmas
with its population of half a million people. Today the palm situation in
the Canaries is not so enchanting, but still deserves attention.
La
Gomera
The most interesting
island of all for palms is La Gomera: thousands of P canariensis live
in the most diverse landscapes, from desert to waterfalls, showing every
possible aspect that this mighty palm can assume. La palmera is
extremely respected by the islanders, los gomeros, because it is
still a source of guarapo, palm honey. This tasty product is regularly
hand-extracted from incisions made in the apical bud without killing the
palm and then sold in the island's markets. One of the most beautiful palmerales
of all the seven islands is found in the majestic scenery of Valle Gran
Rey: a canyon with 700-m high vertical dry cliffs of volcanic lava, which
hang above the very humid terraced floor, intensively cultivated with bananas
(Musa 'Dwarf Cavendish'), Arundo donax, and P canariensis.
The valley is entirely free of P dactylifera. The only exotic palms
are a few washingtonias and Roystonea sp. The entire island is
a biosphere reserve and Valle Gran Rey is its pearl. It is not possible
to build even a small wall without using local techniques and styles.
Gran
Canaria
In Gran Canaria the
environmental deterioration caused by man during the last centuries reduced
the wild palm population to small isolated stands. The palmeral of
Maspalomas is quite small and disturbed, but still needs mention for the
beautiful landscape that surrounds it -- a huge plain covered with Sahara-desert-like
dunes of fair sand, the Oasis de Maspalomas. The true palmeral now belongs
to a hotel, and has been "enriched" by planting a lawn and adding
many P dactylifera. Fortunately the sand dunes are now a nature
reserve and include some scattered palm groves, growing in wild conditions
within a curious sand-loving, xerophytic vegetation of Mediterranean origin
-- a mostly thornless scrub with Tamarix as the dominant shrub.
During the last few years a high number of young P canariensis (I
estimate about 40,000) have been planted all over the island, along roads
and in abandoned fields that cover so much of the land...
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