Chamaerops

Chamaerops is a genus of flowering plants in the family Arecaceae. It contains only one species, Chamaerops humilis, variously called European fan palm or the Mediterranean dwarf palm. It is one of the most cold-hardy palms and is used in landscaping in temperate climates.

Apart from the universally accepted Chamaerops humilis, there are a few potential taxa of unresolved status, plus numerous species synonymised under Chamaerops humilis. The genus Chamaerops is closely related to the genus Trachycarpus. The genera differ in that Trachycarpus lacks the clumping habit (only forms single stems without basal suckers), the spiny leaf stems (spineless in Trachycarpus), and in small details of the flower anatomy.

The species Chamaerops humilis itself has two accepted varieties as follows:

There also are at least three cultivars: C. humilis var. humilis 'Nana', C. humilis 'Vulcano', and C. humilis 'Stella'. C. humilis 'Vulcano' is a compact, thornless cultivar that may be silvery, but less so than var. argentea. The leaves tend to be thicker, and the appearance of the plant is bushier than var. humilis or var. argentea.

Chamaerops humilis is a shrub-like clumping palm, with several stems growing from a single base. It has an underground rhizome which produces shoots with palmate, sclerophyllous leaves.

The stems grow slowly and often tightly together, eventually reaching 2–5 m (10–20 ft) tall with a trunk diameter of 20–25 cm (8–10 in). It is a fan palm (Arecaceae tribe Corypheae), and as such, has leaves with petioles terminating in rounded fans of 10–20 leaflets. Each leaf is up to 1.5 m (5 ft) long, with leaflets 50–80 cm (20–30 in) long. The petioles are armed with numerous sharp, needle-like spines; these may protect the stem growing point from browsing animals.

The flowers are borne in dense, short inflorescences at the tops of the stems. The plants usually, but not invariably, are dioecious with male and female flowers on separate plants. The prophyll covers the flowers on the inflorescence 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 fruits are bright green, turning to dull yellow to brown as they ripen during autumn (September–November). The seed (usually 0.6–0.8 g or 1⁄50–3⁄100 oz) contains a small cylindrical embryo, which is surrounded by several layers, from inner to outer as follows:

Chamaerops humilis is one of only two palm species native to continental Europe, the other being Phoenix theophrasti. It is mainly found in southwestern Europe, over all the south coasts of Spain and Portugal, central and southern Italy, parts of the southern Mediterranean coast of France and Monaco, on the islands of Malta, Sicily, Sardinia, Corsica, and the Balearic Islands, as well as North Africa in Morocco, Algeria and Tunisia. It is one of the northernmost naturally occurring palms in the world, with the northernmost native standing in Genoa, Italy, at 44°N. Although not naturally occurring far north from the Mediterranean, Chamaerops humilis grows well as far north as southern England.