Chamaerops
Encyclopedia
Chamaerops is a genus of flowering plant
s in the family Arecaceae
(palm family), comprising a single species Chamaerops humilis (European fan Palm or Mediterranean dwarf Palm), representative of the Pre-Pliocene paleo-tropical ancestral lineages in the area.
(Spain
, Portugal
, France
, Italy
and Malta
) and northwest Africa
(Morocco
, Algeria
, Tunisia
). It is the northernmost naturally occurring palm in the world, with the northernmost
localities at Hyères-les-Palmiers
, on the Mediterranean coast of southern France
, at 43° 07' N, and on the island of Capraia
off the Italian coast, at 43° 04' N.
It also occurs as an ornamental plant
in other Mediterranean countries (e.g., Lebanon), the United States (California, Texas, Florida), and even in the United Kingdom.
It is a shrub
-like clumping palm, with several stems growing from a single base. The stems grow slowly and often tightly together, eventually reaching 2–5 m tall with a trunk diameter of 20–25 cm. It is a fan palm (Arecaceae tribe Corypheae), with the leaves
with a long petiole terminating in a rounded fan of 10-20 leaflets; each leaf is up to 1-1.5 m long, with the leaflets 50–80 cm long. It also has numerous sharp needle-like spines produced on the leaf stems; these protect the stem growing point from browsing animals. The flower
s are borne in dense, short inflorescences at the top of the stems; it is usually (but not invariably) dioecious
with male and female flowers on separate plants. The prophyll covers the flowers until the sexual phase (anthesis) and then splits open apically into two triangular lobes. The number of flowers per inflorescence is highly variable for both male and female plants, depending on the size of the inflorescence. Female flowers are tri-ovulate. Unripe fruit
s are bright green, turning to dull yellow to brown when ripe during the fall (September–November). The seed (usually 0.6–0.8 g) comprises a small cylindrical embryo, which is surrounded by several layers, from inner to outer: (1) a nutritious endosperm, (2) a wide woody layer or endocarp, (3) a fleshy and fibrous mesocarp (the pulp), and (4) the thin outer layer or exocarp. It has an underground rhizome which produces shoots with palmate, sclerophyllous leaves.
There is one species with two accepted varieties
and two cultivars
It is closely related to the genus Trachycarpus
from Asia
, differing in clumping habit (Trachycarpus only forms single stems without basal suckers), the spiny leaf stems (spineless in Trachycarpus), and in small details of the flower anatomy.
It is adapted to a Mediterranean climate
with cool, moist winters and summer drought, and can grow on poor and rocky soils. It is one of the hardier palms
, tolerating winter frosts down to about −12°C. It will make growth even in climates where the summer temperature is in the low 20's C.
It flowers in April–May and is pollinated by a specific weevil, Derelomus chamaeropsis F., (Curculionidae), and perhaps also by wind. C. humilis is engaged in a nursery pollination mutualism with D. chamaeropsis. At anthesis, both male and female plants attract pollinators with floral-like chemical compounds that curiously are released by leaves, and not by flowers. Once pollinating weevils have found a plant (either male or female), they typically stay on the same plant until the end of its anthesis, finding shelter, egg-laying sites and food within inflorescences. When the host plant reaches the end of anthesis, weevils leave the plant and forage to find a new host plant, either male or female. Larval development occurs within rachises of inflorescences of male plants during autumn and winter. At the beginning of the next flowering period, adult weevils emerge from the dry and brittle stems of old inflorescences of the previous year of male plants. Weevils were showed to lay eggs within female inflorescences, but as soon as seeds start to develop, eggs or larvae are destructed.
The ripe pulp of C. humilis has several intriguing ecological functions. First, when ripened, the pulp smells strongly of rancid butter and thus acts as a foraging cue for nocturnal frugivores (e.g., mammalian carnivores suchs as badgers and foxes). Second, it has a germination inhibitory function, ensuring that the seed does not germinate until has been dispersed. And third, the pulp also acts as a chemical and/or physical barrier against invertebrate seed predators (curculioniod beetles). Because of such pulp multifunctionality, fruit ingestion (and thus pulp removal) by carnivores can have both positive and negative consequences for the palm. On the one hand, seeds ingested by carnivores germinate more frequently than non-ingested seeds. On the other hand, ingested seeds experience higher predation by invertebrates than non-ingested seeds. However, because of the high mobility of carnivores, their dispersal service appears paramount given the severe fragmentation and isolation of most C. humilis populations across the highly humanized Mediterranean basin.
It is used massively in gardening and landscaping in many parts of the world. The leaves of the adult plants have been used in basketweaving to make mats, carrier baskets, and brooms. The young unopened leaves are treated with sulphur to make them softer and supple and are then used for finer work. The husk, known in southern Spain as "higa", is edible before its full development. The fruits are not edible but have been traditionally used in medicine as an astringent because of their bitterness and high tannin content.
Because its natural habitat is rapidly declining due to urbanization and other human activities, conservation concerns and protection regulations of this Mediterranean endemism are rising. In some areas, including its northernmost native location, it is seriously threatened by an introduced South American moth
Paysandisia archon
.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s in the family Arecaceae
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
(palm family), comprising a single species Chamaerops humilis (European fan Palm or Mediterranean dwarf Palm), representative of the Pre-Pliocene paleo-tropical ancestral lineages in the area.
Distribution
It is the only palm species native to continental Europe. It is mainly found in southwestern EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
(Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
and Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
) and northwest Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
(Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
, Tunisia
Tunisia
Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area...
). It is the northernmost naturally occurring palm in the world, with the northernmost
The world's most northern
This is a list of various northernmost things on earth.- Cities and settlements :See also: Northernmost settlements, Northernmost cities and towns-Geography:-Animals:-General:-Shrubs:-Trees:-Culture and music:-Sport :- Religion :...
localities at Hyères-les-Palmiers
Hyères
Hyères , Provençal Occitan: Ieras in classical norm or Iero in Mistralian norm) is a commune in the Var department in the Provence-Alpes-Côte d'Azur region in southeastern France....
, on the Mediterranean coast of southern France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, at 43° 07' N, and on the island of Capraia
Capraia
Capraia, called Capraria in ancient times, is an island of Italy, part of the Tuscan Archipelago, off the northwest coast; it is also a comune belonging to the Province of Livorno. It is 62 km from the city of Livorno by sea, and 32 km northwest of the island of Elba; it is slightly...
off the Italian coast, at 43° 04' N.
It also occurs as an ornamental plant
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
in other Mediterranean countries (e.g., Lebanon), the United States (California, Texas, Florida), and even in the United Kingdom.
Description
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
-like clumping palm, with several stems growing from a single base. The stems grow slowly and often tightly together, eventually reaching 2–5 m tall with a trunk diameter of 20–25 cm. It is a fan palm (Arecaceae tribe Corypheae), with the leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
with a long petiole terminating in a rounded fan of 10-20 leaflets; each leaf is up to 1-1.5 m long, with the leaflets 50–80 cm long. It also has numerous sharp needle-like spines produced on the leaf stems; these protect the stem growing point from browsing animals. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are borne in dense, short inflorescences at the top of the stems; it is usually (but not invariably) dioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
with male and female flowers on separate plants. The prophyll covers the flowers until the sexual phase (anthesis) and then splits open apically into two triangular lobes. The number of flowers per inflorescence is highly variable for both male and female plants, depending on the size of the inflorescence. Female flowers are tri-ovulate. Unripe fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s are bright green, turning to dull yellow to brown when ripe during the fall (September–November). The seed (usually 0.6–0.8 g) comprises a small cylindrical embryo, which is surrounded by several layers, from inner to outer: (1) a nutritious endosperm, (2) a wide woody layer or endocarp, (3) a fleshy and fibrous mesocarp (the pulp), and (4) the thin outer layer or exocarp. It has an underground rhizome which produces shoots with palmate, sclerophyllous leaves.
There is one species with two accepted varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....
and two cultivars
- Chamaerops humilis var. argentea André (syn. var. cerifera). Northwest Africa. Leaves glaucous.
- Chamaerops humilis var. humilis. Southwest Europe. Leaves green.
- Chamaerops humilis 'Vulcano'. Compact, thornless cultivarCultivarA cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
- may be silvery, but less so than argentea. The leaves tend to be thicker, and the appearance of the plant is bushier than var. humilis or var. argentea. - Chamaerops humilis var. humilis
It is closely related to the genus Trachycarpus
Trachycarpus
Trachycarpus is a genus of ten species of palms native to Asia, from the Himalaya east to eastern China. They are fan palms , with the leaves with a bare petiole terminating in a rounded fan of numerous leaflets. The leaf bases produce persistent fibers that often give the trunk a characteristic...
from Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, differing in clumping habit (Trachycarpus only forms single stems without basal suckers), the spiny leaf stems (spineless in Trachycarpus), and in small details of the flower anatomy.
Ecology and Interactions with Animals
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...
with cool, moist winters and summer drought, and can grow on poor and rocky soils. It is one of the hardier palms
Hardy palms
Hardy palms are any of the species of palm that are able to withstand colder temperatures and thrive in places not typically considered in the natural range for palms. Several are native to higher elevations in Asia and can tolerate hard freezes with little or no damage...
, tolerating winter frosts down to about −12°C. It will make growth even in climates where the summer temperature is in the low 20's C.
It flowers in April–May and is pollinated by a specific weevil, Derelomus chamaeropsis F., (Curculionidae), and perhaps also by wind. C. humilis is engaged in a nursery pollination mutualism with D. chamaeropsis. At anthesis, both male and female plants attract pollinators with floral-like chemical compounds that curiously are released by leaves, and not by flowers. Once pollinating weevils have found a plant (either male or female), they typically stay on the same plant until the end of its anthesis, finding shelter, egg-laying sites and food within inflorescences. When the host plant reaches the end of anthesis, weevils leave the plant and forage to find a new host plant, either male or female. Larval development occurs within rachises of inflorescences of male plants during autumn and winter. At the beginning of the next flowering period, adult weevils emerge from the dry and brittle stems of old inflorescences of the previous year of male plants. Weevils were showed to lay eggs within female inflorescences, but as soon as seeds start to develop, eggs or larvae are destructed.
The ripe pulp of C. humilis has several intriguing ecological functions. First, when ripened, the pulp smells strongly of rancid butter and thus acts as a foraging cue for nocturnal frugivores (e.g., mammalian carnivores suchs as badgers and foxes). Second, it has a germination inhibitory function, ensuring that the seed does not germinate until has been dispersed. And third, the pulp also acts as a chemical and/or physical barrier against invertebrate seed predators (curculioniod beetles). Because of such pulp multifunctionality, fruit ingestion (and thus pulp removal) by carnivores can have both positive and negative consequences for the palm. On the one hand, seeds ingested by carnivores germinate more frequently than non-ingested seeds. On the other hand, ingested seeds experience higher predation by invertebrates than non-ingested seeds. However, because of the high mobility of carnivores, their dispersal service appears paramount given the severe fragmentation and isolation of most C. humilis populations across the highly humanized Mediterranean basin.
Uses and Threats
Due to its rusticity and resprouting ability after fire, it has a high ecological value for preventing erosion and desertization. This charismatic palm is thus considered one of the most important species in the natural conformation of the "garrigues" and "macchias" of the Mediterranean coastline.It is used massively in gardening and landscaping in many parts of the world. The leaves of the adult plants have been used in basketweaving to make mats, carrier baskets, and brooms. The young unopened leaves are treated with sulphur to make them softer and supple and are then used for finer work. The husk, known in southern Spain as "higa", is edible before its full development. The fruits are not edible but have been traditionally used in medicine as an astringent because of their bitterness and high tannin content.
Because its natural habitat is rapidly declining due to urbanization and other human activities, conservation concerns and protection regulations of this Mediterranean endemism are rising. In some areas, including its northernmost native location, it is seriously threatened by an introduced South American moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
Paysandisia archon
Paysandisia archon
Paysandisia archon is a moth of the family Castniidae. It is native to Uruguay and central Argentina and has been accidentally introduced to Europe, where it is spreading rapidly. It is considered the only member of the genus Paysandisia....
.