What We Know and What We Do Not Know about Dragon Trees?

Abstract

This article is a broad review focused on dragon trees—one of the most famous groups of trees in the world, well known from ancient times. These tertiary relicts are severely endangered in most of the area where they grow. The characteristic features of the dragon tree group are described and the species belonging to this group are listed. This review gathers together current knowledge regarding the taxonomy, evolution, anatomy and morphology, physiology, and ontogeny of arborescent dragon tree species. Attention is also paid to the composition, harvesting, medicinal, and ethnobotanical use of the resin (dragons’ blood). An evaluation of population structure, distribution, ecology, threats, and nature conservation forms the final part of the review. In the conclusions we recommend further avenues of research that will be needed to effectively protect all dragon tree species.

Development of a population of Boswellia elongata Balf. F. in Homhil nature sanctuary, Socotra island (Yemen)

“…Because young trees are missing, we predict that this population is moving towards extinction. This is in line with other autochthonous tree species on Socotra, where intensive grazing is seen as the major threat Attore et al 2011;Brown and Mies 2012;Lvončík et al 2013;Maděra et al 2020). Pastoralism has been practised on Socotra for at least several centuries (Miller and Morris 2004; Van Damme and Banfield 2011; Jansen van Rensburg and Hopper 2017).…”

Complete Chloroplast Genome Sequence and Phylogenetic Inference of the Canary Islands Dragon Tree (Dracaena draco L.)

“…The morphology of the inflorescences of these two genera is very similar, but they are different from flowers of the species of dracaenas called the dragon trees [5]. This group contains 11 species, which are distinguished by succulent leaves and production of a red resin known as dragon blood [6]. These distinctive plants, which are tertiary relicts, are of great interest due to their cultural heritage to humanity, important ecological role as umbrella species [6], and the fact that they do not form a strongly supported monophyletic clade within Dracaena sensu lato in molecular studies, despite similar morphology [1,4].…”

“…This group contains 11 species, which are distinguished by succulent leaves and production of a red resin known as dragon blood [6]. These distinctive plants, which are tertiary relicts, are of great interest due to their cultural heritage to humanity, important ecological role as umbrella species [6], and the fact that they do not form a strongly supported monophyletic clade within Dracaena sensu lato in molecular studies, despite similar morphology [1,4]. The first described species of the whole Dracaena genus and the most famous dragon tree is Dracaena draco L., which occurs in a subtropical climate in thermo-sclerophyllous zones in Morocco and Atlantic islands including the Canary Islands, Cabo Verde and Madeira.…”

Exploring the historical distribution of Dracaena cinnabari using ethnobotanical knowledge on Socotra Island, Yemen

“…The Socotra Dragon's Blood Tree (Dracaena cinnabari) is a ag-ship species of Socotra [ 46,47 ]. It was a very important tree in ancient times due to a historically highly prized product called dragon's blood, a red resin extracted for a wide range of uses including coloring and local medicine [ 39,48 ]. Some believe that the name Socotra could even be a derived from "Sukkatira" or contracted from "suq qatra", where suq is the Arabic word for "market" and qatra for "dragon's blood" [ 49,50 ].…”

“…Overgrazing destroying the natural regeneration [ 104 ] and very slow growth of recruitment [ 105 ] do not allow the trees to escape from browsing zone [ 47,48,106 ]. Therefore, these are known as the main reasons of population decline.…”