Plant of the Month

February 2019

Posidonia oceanica (L.) Delile


Posidonia oceanica the marine plant that causes unwarranted fear in so many swimmers that say "do not swim above the seaweed," is an Angiosperm monocotyledon and not a seaweed (alga). It is more widely known as Poseidonia, as god Poseidon had chosen it as its favorite plant in antiquity.

It is an endemic Mediterranean seagrass, that spreads throughout almost all of the Mediterranean coastal zone. It grows in soft bottom substrates, creating extensive meadows that can reach to 45 m depth, when the waters are clear, providing food, protection and substrate to plenty organisms. Its contribution to primary productivity, biodiversity and indirect fishing is enormous, as it can accommodate up to 1,000 different species and provides equally important ecosystem services such as coastal protection from waves and erosion, recycling of inorganic nutrients, and "filtering" of the water column. Over the last decade, its ability to long-term carbon storage (C) has also been greatly emphasized, since it can influence the global cycle of C and the phenomena of climate change.

Posidonia meadows are threatened by anthropogenic activities (fishing with towed gear, coastal projects, etc.) all over the Mediterranean. Considering all the above and in conjunction with the very slow growth of the species (a meadow can make 100 years to recover), the species is protected under International Conventions (Barcelona Convention 1976 and Bern Convention 1979) as well as European Directives and Regulations (Habitats Directive (HD, 92/43 / EEC), European Regulation for Mediterranean Fisheries (1967/2006).

C. Katsaros, V. Papathanasiou

January 2019

Malus trilobata (Poir.) C.K. Schneid.

DSC 1880.Malus-trilobata
DSC 2010.Malus-trilobata
DSC 2841
DSC 6798
DSC 7505

Malus trilobata is one of the rarest trees of the Greek flora. It is an east Mediterranean element with constricted and disjunct populations in Israel, Lebanon, Syria and Asia Minor. In Europe, it extends only in the extreme NE Greece, in Evros prefecture, between the villages of Dadia and Makri.

It grows in maquis, in deciduous scrub and in open thermophilous woodlands, at an altitude of 150-350 m. It is a small, deciduous tree up to 10 m tall, with characteristic lobed leaves, white flowers up to 4 cm in diameter and the fruit is a fleshy yellow-green pome with a diameter of 3 cm. It is flowering late in May and can be easily recognized through the dense vegetation.

In the past, its fruit was retained and consumed by humans, though today it is only used as animal feed. Its wood is rather hard, and therefore it is rarely logged. However, frequent wildfires seriously threaten the Greek population of Malus trilobata, which is estimated to be less than 160 individuals. It is included in the first edition of the Red Data Book of Rare and Threatened Plants of Greece (1995) as Vulnerable.

Giorgos Korakis


Galanthus ikariae Baker

IMG 5749
IMG 5751

Galanthus ikariae is endemic to the Aegean islands (Ikaria, Naxos, Andros, Skyros). It grows in wet and shady places, usually in ravines and deciduous woodlands. Its flowering period starts in late November, peaking during December. It is distinct among the Greek Galanthus species and is considered related to G. woronowii from the Caucasus.

Panayiotis Trigas

November 2018

Centaurea vlachorum Hartvig

Centaurea vlachorum1 Poulis
Centaurea vlachorum2 Poulis
Centaurea vlachorum3 Poulis

Centaurea vlachorum Hartvig was described only in 1981 from the mountains Milia and Aftia and it was initially considered an endemic species of Northern Pindos (N. Greece), but it was recently discovered on mountains of Albania, rendering it a Balkan endemic.

Although the genus Centaurea is represented by a 3-digit figure of species in Greece, C. vlachorum stands out quite easily due to a number of morphological characters, such as leaf shape, indumentum and the thickened stem below the capitulum.

It flowers in summer, in meadows and clearings inside beech and Bosnian pine forests, at elevations higher than 1500 m. a.s.l. and always on ophiolitic geological substrate.

Giorgos Poulis

October 2018

Crocus macedonicus Rukšāns


Crocus macedonicus Rukšāns was only recently discovered (in 2012) on the southern slopes of Mt Vertiskos in Macedonia. Initially, it was believed that this species has a very limited distribution, only in a few places, but afterwards it was proved to exist on all the southern slopes of Mt Vertiskos, at an altitude of 300-700 m; it is considered that Crocus macedonicus distribution tend to be larger. The species is recorded on limestone slopes with low herbaceous vegetation and its flowering period is in October and November.

T. Giannakis