Thrinax radiata

Thrinax radiata

The Florida thatch palm (Thrinax radiata Lodd. ex Schult. & Schult.f., 1830) is an arboreal species belonging to the Arecaceae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Division Magnoliophyta,
Class Liliopsida,
Order Arecales,
Arecaceae family,
Subfamily Coryphoideae,
Tribe Cryosophileae,
Genus Thrinax,
Species T. radiata.
The terms are synonymous:
– Coccothrinax martii (Griseb.) Becc.;
– Coccothrinax radiata (Lodd. ex Schult. & Schult.f.) Sarg.;
– Coccothrinax radiata (Lodd. ex Schult. & Schult.f.) Sarg. ex K.Schum.;
– Porothrinax pumilio H.Wendl.;
– Porothrinax pumilio H.Wendl. ex Griseb.;
– Thrinax aurata Kunth;
– Thrinax elegans Schult. & Schult.f.;
– Thrinax elegantissima Hook.f.;
– Thrinax ferruginea Lodd.;
– Thrinax ferruginea Lodd. ex Mart.;
– Thrinax floridana Sarg.;
– Thrinax gracilis Schult. & Schult.f.;
– Thrinax maritima Lodd.;
– Thrinax maritima Lodd. ex Mart.;
– Thrinax martii Griseb.;
– Thrinax mexicana Lodd.;
– Thrinax mexicana Lodd. ex Mart.;
– Thrinax montana Lodd.;
– Thrinax montana Lodd. ex Mart.;
– Thrinax pumilio Lodd.;
– Thrinax pumilio Lodd. ex Schult. & Schult.f.;
– Thrinax radiata Lodd.;
– Thrinax radiata Mart.;
– Thrinax wendlandiana Becc..

Etymology –
The term Thrinax comes from the Greek “θρῖναξ” (thrinax), which means three-pronged pitchfork but also shovel for winnowing, probably in reference to the shape of the palmate leaves.
The specific epithet radiata comes from the Latin “radiatus, a, um”, that is, surrounded by rays, in reference to the segments of the leaf.

Geographic Distribution and Habitat –
Thrinax radiata is a palm native to an area that includes southern Florida, the Florida Keys and Puerto Rico in the United States, western Cuba, the Bahamas, the Cayman Islands, Jamaica, Hispaniola (Dominican Republic and Haiti), of the eastern coast of the Yucatán Peninsula Mexico, Belize, Honduras and Nicaragua.
Its habitat is that of coastal regions on calcareous or sandy soils near the sea, often covered by sand dunes.
In particular, it grows and develops in coastal dunes and in sub-evergreen and sub-deciduous forests, especially in areas influenced by the winds, however it has been found up to 50 kilometers inland. The palm generally develops in conditions of regions with a humid tropical climate. It is frequently found in clearly tropical coastal habitats such as medium-sized sub-evergreen forests, medium-sized sub-deciduous forests, and in the coastal dunes associated with savannas, mangroves, and swamps of Quintana Roo and Yucatán.
This palm grows preferably in calcareous alkaline soils (rendzinas) and with a high concentration of salts; the height of adult individuals depends on microclimatic and edaphic conditions. In arid areas they grow up to 3 m less than in places where there is an average sub-evergreen forest. It can be found in coastal dunes with very high concentrations of Sodium and Chlorine due to proximity to the sea, and then further inland in low and medium sub-deciduous forests, where the concentration of these nutrients is negligible, suggesting that this species has the ability to adapt to different salinity concentrations in the soil.

Description –
Thrinax radiata is a monoecious palm with a solitary, rarely tufted, erect stem, which, on average, reaches a height of 2-10 m.
The stem has a diameter of 8-12 cm in diameter, of a greyish color with the annular scars of the fallen leaves, spaced on average 5 cm, in the older part, covered by the residues of the leaf bases under the foliage; often presents with a mass of exposed roots at the base.
The leaves are borne by a 40-90 cm long petiole; they are palmate, unduplicated, almost circular and slightly wavy, 1-1.6 m in diameter, of a shiny dark green color with yellow veins above, lighter and opaque below, divided into 50-60 linear-lanceolate segments with a sharp falling apex , 0.8-1 m long in the central part and 5-6 cm wide, united at the base for 1/3-1/2 of their length, except the two central ones which are often entirely united or almost up to the apex.
The leaf sheath is about 60 cm long, deeply fissured at the base at the petiole, opens obliquely from the opposite side, disintegrating into coarse fibers that wrap around the stem.
The inflorescences are produced between the leaves, usually not exceeding their length, erect or slightly arched, curved in fruit, white in colour, initially enclosed by overlapping green bracts covered with tiny whitish scales. The second order ramifications bear hermaphroditic flowers, on a 1.5-2.5 mm long pedicel, fragrant, with a cup-shaped perianth with 6 teeth, 5-10 stamens and a monocarpellar gynoecium.
The fruits are globose, 7-8 mm in diameter, white when ripe.
Inside them there is a single globular seed, 6-7 mm in diameter, light brown in colour.

Cultivation –
Thrinax radiata is an evergreen palm whose leaves are often harvested from the wild and are commonly used to weave hats and other items. The stems are used as poles.
It is a palm of tropical and subtropical areas, where it prefers humid conditions.
From a pedological point of view it prefers well-drained and calcareous soil; it is a salt tolerant plant and mature plants are drought resistant.
It is a palm that grows in nature often along the coasts near the sea on predominantly sandy calcareous soils.
This plant is slow growing, particularly attractive and due to its small size it can be easily placed in any type of garden, even of limited size, with a notable landscape effect in groups or rows.
It can be cultivated in tropical, subtropical and marginally warm temperate climate regions, where as adults it can resist exceptional temperature values down to -2 °C, with possible damage to the foliage.
It requires full sun or at most light shade and perfectly draining soils, not supporting water stagnation, preferably calcareous, but it also adapts to slightly acidic or neutral soils, resists salty winds and short periods of drought, and can therefore be used near the sea and in desert-type gardens.
Young plants can be grown for a long time in pots for the decoration of open spaces, where the climate allows it, and bright interiors, using a soil rich in organic substance with the addition of 30% coarse calcareous sand to improve drainage, with minimum temperatures not lower than 16 °C.
It reproduces by seed, previously kept in water for 3 days, in particularly draining soil kept humid at a temperature of 26-28 °C, with germination times starting from one month.

Customs and Traditions –
Thrinax radiata is a palm known by various common names; among these we report: Florida thatch, Jamaican thatch, saltwater palmetto, sea thatch, silk-top thatch palm, thatch palm, top thatch palm (English); guano campeche, guano de costa (Cuba); thatch (Jamaica); latanier-la-mer (Haiti), chit, chi-it (Mexico); guanillo (Dominican Republic).
This palm can be distinguished from the similar-looking Coccothrinax genus by its white drupes, while Coccothrinax drupes are black or yellow. Another distinctive feature of Thrinax is the divided leaf bases, whereas the leaf bases in the Coccothrinax genus are fused, so much so that it was once thought to belong to the related genus Coccothrinax.
The fruits of this palm are edible and represent an important source of food for avifauna, the stems are used in construction and the long-lasting dry leaves as a covering for rural homes and tourist structures and for the manufacture of hats, baskets , mats, brooms, lobster traps and other handicrafts.
Ecologically its seeds are eaten and presumably dispersed by many animals including bats, spider monkeys, toucans, armadillos and deer. The young leaves are also eaten by spider monkeys, while the mature ones serve as a refuge for various species of bats. In Florida (Elliott Key in particular), the invasive Mexican gray squirrel (Sciurus aureogaster) has had an extremely negative impact on T. radiata populations. It uses palm fibers as nesting materials and consumes the palm itself, often killing the plant.
This species appears to be globally safe; however, it is rare at the northern edge of its range in Florida. Although it is commonly grown as a landscape plant in residential areas, its wild state in Florida is sparse and it is only rarely encountered. There are currently no specific efforts to reduce the severity of this status in the United States. There are, however, restrictions on collection in Mexico, where human use has had a major impact on T. radiata populations.
In fact, this palm is commonly used as a landscape tree along roads and in residential areas of South Florida (zones 10b and 11a). Today it is widely planted outside its natural historical range in southern Florida and the Caribbean due to its ability to grow in various conditions. It is used by gardeners and can be grown in containers or arboretums, which showcase the prolific inflorescences and fruits of this species.
Its fronds are the most used part of the palm, being used in broom making, crafts and food packaging. Its logs have recently been used to build lobster traps by fishermen in the Yucatán Peninsula.
However, the greatest threat facing populations of this species is the destruction of medium-sized forests, coastal vegetation and the local use of logs as building material. In the Yucatán Peninsula, illegal cutting and sale of this species is common and lacks adequate controls.
For the reasons indicated above, this species is classified as threatened in Mexico, according to the SEMARNAT 059-ECOL-2001 standard.
However, this palm is not included in any of the 3 appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) nor is it on the Red List of the International Union for Conservation of Nature (IUCN).

Preparation Method –
Thrinax radiata is a palm known and used both for bird food purposes and for the use of its materials.
The fruits of this palm are an important source of food for avifauna.
The stems, however, are used in construction and the long-lasting dry leaves are used as a covering for rural homes and tourist facilities and for the manufacture of hats, baskets, mats, brooms, lobster pots and other handicraft objects.
The leaves, in particular, are used to weave hats and other items.
The stems are sometimes used as poles.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/276206268/original.jpeg

Attention: Pharmaceutical applications and food uses are indicated for informational purposes only, they do not represent in any way a medical prescription; we therefore decline any responsibility for their use for healing, aesthetic or food purposes.