Zelkova sicula

Zelkova sicula

The Sicilian zelkova (Zelkova sicula Di Pasquale, Garfi & Quézel, 1992) is an arboreal species belonging to the Ulmaceae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Division Magnoliophyta,
Class Magnoliopsida,
Rosales Order,
Ulmaceae family,
Genus Zelkova,
Species Z. sicula.

Etymology –
The term Zelkova derives from the Caucasian idiom, as demonstrated in the Georgian name, ძელქვა (dzelkva), ძელ dzel meaning “bar, beam” or “crossbar” and ქვა kva meaning “rock”.
The specific Sicilian epithet refers to its discovery in Sicily, whose name comes from the Greek Sikelìa, from the name of the people who inhabited the island: the Siculi, in Greek Sikeloi, originating from central Italy.

Geographic Distribution and Habitat –
Zelkova sicula is an endemic plant of the Iblei Mountains (Sicily) and present in two small populations near the eastern coast of the island; one in the Pisano forest of Buccheri, the highest municipality in the Iblei (SR) and the other in the Ciranna di Melilli district (SR).
The only existing population of Z. sicula, discovered in 1991, is located on the northern side of the Iblei Mountains, in south-eastern Sicily, and is made up of 200-250 specimens in the Pisano wood, an oak forest of about half a hectare that grows in 450 m above sea level, near Buccheri, and in the Melilli area.
Its discovery habitat was inside a ravine bottom with an underground water reserve all year round, between 318 and 526 m. above sea level.

Description –
The Zelkova sicula is a plant that grows in the form of a deciduous shrub or small tree (even if the potential height is still unknown but, certainly, of arboreal habit), sometimes with a bushy habit, up to about 5 m tall.
The bark is grey, smooth in young and dwarf trees, probably exfoliating eventually into thin plates. The twigs are pubescent and ash-brown in colour.
The leaves are ovoid in shape, small, sparsely lobed, leathery and hairy, similar to those of an elm, they are distinguished from it by the roughly serrated margin and the symmetry of the blade (asymmetric in the elm); the leaves are 1–5 cm long and 0.5-3.5 cm wide, with a 1–4 mm petiole; the margins have 6-8 lobes on each side; the leaves are wrinkled on both surfaces due to the presence of short stiff hairs, more abundant along the veins of the lower page.
In the Bosco Pisano clone the leaf is ovate and wider near the base, about 5 × 3 cm, with (3–)4–6 pairs of main veins, each terminating in a large tooth and with occasional intermediate teeth or forked veins . In the C.da Ciranna clone the leaf is broadly lanceolate, about 6 × 3 cm, with (3–)5–8 pairs of major veins ending in a large tooth.
The fruit is about 3 mm wide, irregular in shape.

Cultivation –
Zelkova sicula is a recently discovered plant, so much so that it is the most recently discovered European tree species.
In 1991, the Sicilian ecologist Giuseppe Garfi was carrying out a floristic survey on the Iblei Mountains in the eastern part of the island (Garfi 2013); during this inspection in a rocky gully of the Pisan Woods less than 200 m long, he glimpsed in a ravine a couple of hundred stunted and swarming bushes whose foliage Garfi did not recognize. They were soon identified as a Zelkova species, closely resembling Z. abelicea (Zelkova abelicea (Lam.) Boiss.), whose natural distribution is limited to the island of Crete, over 700 km to the east.
Genetic analysis showed that these plants were triploid, rather than diploid like other Zelkova species, indicating an ancient hybrid origin. They had survived in an increasingly arid climate inside the ravine, where water flowed underground year-round, thanks to the genus’s ability to suck copiously. The pollen of these trees is abnormal and no seedlings have been raised from them; the population of the Bosco Pisano therefore represents a single clone. Although they were widely browsed by free-roaming livestock, local farmers were unaware of these plants (Kozlowski et al. 2018).
A concerted effort was made to safeguard the species and in 2009 a second, slightly larger population was discovered in another, larger valley near Ciranna, 17 km to the east and at a lower altitude in the Iblean Mountains.
The population of c.da Ciranna is another vegetatively propagated clone, and has a slightly different appearance from that of Bosco Pisano, as previously described.
The overall population extends to nearly 2,000 bush suckers. Violent fires and increasingly severe droughts represent the main threats to the survival of the species; 23 suckers from Bosco Pisano dried up due to drought stress in 2007 (IUCN 2017; Kozlowski et al. 2018). Each of the two populations has now been fenced against grazing.
As regards its propagation and conservation, given the inadequacy of the microclimates in which the species found itself abandoned, Z. sicula immediately presented itself as a strong candidate for ex situ conservation.
Thus a shoot from the population of the Pisano forest was transplanted in 1993 into a garden in Buccheri, which at 820 m in the Iblei Mountains receives considerably greater rainfall; by 2012 this has formed a shapely tree 7 m tall and continues to grow quite vigorously (Kozlowski & Gratzfeld 2013).
Furthermore, it was immediately demonstrated that Z. sicula was suitable for translocation (assisted migration), i.e. the artificial creation of new populations as an in situ conservation action.
Four new populations have established themselves in the wetter mountains of northern Sicily and are growing much more vigorously than the parent plants, although the snow, ironically, has damaged some saplings (Garfi 2018); a fifth new population was planted near the existing one in Bosco Pisano, for comparison.
It is possible that Z. sicula is even better adapted to the more northern conditions of Europe. D
As of 2010, micropropagation of cuttings for more widespread ex situ conservation and commercial sale is coordinated by the National Botanical Conservatory of Brest in France (Garfi 2013). Both the Pisano and Ciranna woodland populations are now well established in collections across Europe and both have been given to specialist nurseries.
The potential resistance of this tree, as suggested above, is still a matter of debate, however the saplings have also established themselves as far north as the UK and promise to create much larger plants than wild ones.

Customs and Traditions –
The Zelkova sicula, as mentioned, is a plant discovered in 1991, during an inspection to carry out a forestry inventory in the countryside of south-eastern Sicily.
The botanist Giuseppe Garfì, after having collected some samples, began meticulous research in an attempt to classify it, without however reaching any conclusions. With the help of Prof. Quezel of the University of Marseille, one of the world’s leading experts on Mediterranean flora, the surprise was not long in coming. The researchers were faced with what was considered one of the greatest botanical discoveries to have occurred in Italy in the last century; it was a new species: the Zelkova sicula.
It should be noted that, once widespread throughout the Mediterranean, Zelkova is a relict plant of the tertiary flora which today is found only in some refuge areas of the northern hemisphere. About 30,000 years ago, due to the Quaternary glaciations, this genus became extinct throughout the European continent, surviving only in two ‘ecological niches’, respectively on the mountains of the island of Crete (Zelkova abelicea) and in Sicily (Zelkova sicula) .
Today the Sicilian populations are found, as observed, only on the Iblei Mountains, in the territories of Buccheri (260 plants) and Melilli (1540 plants). The enormous botanical and environmental value of Zelkova sicula and the small number of living specimens place the plant in the IUCN list of the 50 species at greatest risk of extinction in the Mediterranean, a reason that pushed the Ministry of the Environment and Land Protection, first, and the European Union, afterwards, to finance projects for its conservation.
In fact, despite being included in two sites of community importance (SCI), the populations of Zelkova sicula were not subject to any legal protection measure until 2013. A paradoxical situation that has been overcome thanks to the Protection Decree of the President of the Region (D.P.R.S. n°312 of 05/27/2013), issued as part of the interesting Zelkov@zione project, which is part of the LIFE program of the European Commission and which sees as coordinating partner the Regional Department of the Environment of the Sicilian Region (DRA), and as associated partners the Regional Department of Rural and Territorial Development of the Sicilian Region (DRSRT), the National Research Council – Institute of Biosciences and BioResources of Palermo (CNR-IBBR), the Conservatoire Botanique National of Brest (CBNB) and Legambiente Onlus.
The project presents itself as a great challenge as it must be carried out through some fundamental stages including the census of the entire population, the conservation and restoration of the natural habitat, the study of the genetic structure of the populations, the production of propagation materials, the spread of the species and obviously the creation of awareness and education campaigns.
The team of researchers from the CNR of Palermo, in collaboration with the CBNB, developed a specific propagation protocol which was followed by the identification of four pilot sites, in some Sicilian woods, for a first reintroduction campaign into nature (‘assisted colonization’).
Furthermore, a new nucleus of Zelkova sicula plants was reintroduced on 5 December 2019 in a new site located in the Iblei Mountains at approximately 880 m above sea level, in the Bosco Contessa district (Free Consortium of Syracuse). The site is included within the Regional Forestry State Property managed by the DRSRT. In total, 18 seedlings aged from 1 to 3 years obtained from in vitro cultures were planted at the CNR-IBBR laboratories in Palermo. The planting, carried out by DRSRT forestry workers with the coordination of CNR-IBBR personnel, brings the total number of reintroduction sites of the target species to 5.
On May 15, 2019, two plants of Zelkova sicula, obtained from in vitro cultures at the CNR-IBBR laboratories, were also planted in the Botanical Garden of Palermo, enriching the important botanical heritage of the prestigious Sicilian institution. The two specimens were placed respectively in the Ulmaceae section of the Linnaean quarters and in the Mediterranean hill, which hosts a collection of endemics originating from the entire Mediterranean Basin
To date, however, Z. sicula is considered by the IUCN to be a critically endangered species and has been included in the list of the 50 most threatened botanical species in the Mediterranean area.

Preparation Method –
Zelkova sicula is one of those plants, like Abies nebrodensis, whose objective is, obviously, conservation and diffusion.
There are therefore no uses other than in situ and ex situ conservation.

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://www.treesandshrubsonline.org/articles/zelkova/zelkova-sicula/

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.