Malus trilobata, the Lebanese wild apple, also known as the erect crab apple, Turkish apple, three-lobed apple or deer apple, is a species of apple (Malus) in the rose family (Rosaceae). It has a discontinuous range in the eastern Mediterranean, including Thrace, coastal Anatolia and the Levant, but almost always as a rare species. First described in 1810 as Crataegus trilobata, it has a complex taxonomic history, and some authorities place it in the segregate genus Eriolobus, as Eriolobus trilobatus, either alone or together with the closely related Italian crabapple (Malus florentina) from the central Mediterranean. The species is characterised by shiny, maple-like leaves, particularly large, white flowers, large and edible fruits and a narrow growth form. Due to its attractive shape, bloom and foliage along with its drought and frost tolerance, it has found increasing interest in gardening and landscaping. Additionally, its chemical composition and associated microbiome has attracted research investigating its medical and antimicrobial properties. However, the species is thought to be threatened and declining, primarily due to human encroachment and habitat destruction, including from wildfires.
Taxonomy and evolution
Taxonomic history
The taxonomic history of Malus trilobata is complex, reflecting its unique morphology. The species was formally described by Jean Louis Marie Poiret based on a specimen, the type, that Jacques Labillardière had collected in Lebanon, in 1810. Poiret, however, considered the species to be a hawthorn, and consequently placed it in the genus Crataegus, as Crataegus trilobata. Since then, the species has also been placed within the genera Pyrus, as Pyrus trilobata, Sorbus, as Sorbus trilobata, Cormus, as Cormus trilobata, and Malus, as well as in Eriolobus, whereby the latter was variably considered to include either only M. trilobata or also M. florentina. Many authorities have sought to emphasise the species' distinctiveness by assigning it to unique genera, sections or subsections. Today, two competing treatments prevail: under the one that is currently (as of October 2025) accepted by Plants of the World Online, the species is considered to belong to Malus. Traditionally, many researchers have further classified the species within its own section, Eriolobus, but the validity of these subgroupings on morphological grounds in Malus has been questioned more recently. Alternatively, some authorities and databases separate M. trilobata within its own genus Eriolobus, as Eriolobus trilobatus.
Both classifications, in Malus and in Eriolobus, appear to be supported by research findings. M. trilobata resembles other Malus species in floral morphology, and it is similar to some Malus species in leaf shape. For these reasons, the Polish dendrologist Kazimierz Browicz (1969) considered it to be most closely related to Malus doumeri and, to a lesser extent, to Macromeles tschonoskii (which is also often placed in Malus), both of which are native to East Asia. On the other hand, M. trilobata differs in the grit cells in its fruits, which are more commonly associated with Pyrus, even though they also occur in some other Malus species. Furthermore, phytochemical studies have shown that, uniquely in Malus, trilobatin replaces phloridzin as the main phenolic compound in the leaves in M. trilobata, which may similarly be taken to indicate a need for separation.
Several varieties of the species have been described, including Eriolobus trilobatus var. oxyloba and Eriolobus trilobatus var. sorgerae, the latter of which was collected by Austrian botanist Friederike Sorger in Gömbe, Antalya Province, Turkey, and subsequently described as a distinct variety by Browicz, who emphasised its much smaller leaves, in 1976. Current consensus, however, recognises no subdivisions.
Modern taxonomy and evolution
Phylogenetic studies based on plastid and nuclear DNA indicate that Malus trilobata falls between other species normally classified as Malus, and it appears to be sister to M. florentina, with both species often, but not always, positioned together on a branch that also contains the North American species prairie crabapple (Malus ioensis), southern crabapple (M. angustifolius) and sweet crabapple (M. coronaria). In a study by Liu and colleagues (2022), this branch, called Clade II (a clade being a group of all organisms that descend from a common ancestor), is shown to either be basal to the rest of Malus, in nuclear phylogenies, or to be sister to Pourthiaea and thus closer to other Maleae such as Sorbus and Aronia than to Malus proper, in plastid phylogenies. This discordance between nuclear and plastid phylogenies, the authors proposed, could be due to several factors during the speciation process: incomplete lineage sorting, that is, the inheritance of an incomplete set of alleles from the most recent common ancestor; allopolyploidy, that is, the inheritance of more than two copies of alleles; or hybridisation, the crossing of species. All of these were important mechanisms underlying the evolution of the Maleae, the apple tribe, rendering the reconstruction of its evolutionary history difficult. Liu and colleagues proposed hybridisation as the most likely scenario, whereby the ancestor of Clade II hybridised with the ancestor of Pourthiaea, so that all its descendants, including M. trilobata, inherited Pourthiaeas chloroplast DNA through a process known as chloroplast capture.
According to Liu and colleagues (2022), Malus originated in North America and East Asia, most likely in the middle Eocene, between 41.2 and 44.39 million years ago. Also according to this study, Clade II, the clade M. trilobata belongs to, originated in western North America and subsequently spread to Europe and western Asia in the late Eocene via the North Atlantic Land Bridge. The split between Malus trilobata and its sister M. florentina, the two representatives of this clade in western Eurasia, was estimated to have occurred already in the early Oligocene, 32.81 million years ago. Malus antiqua, a fossil species with lobed leaves from the Pliocene (5.33–2.58 Mya) of Europe, recovered in Romania, is considered to be ancestral to M. trilobata or M. florentina.
Etymology The genus name Malus is derived from Latin malus, meaning "apple tree". The epiphet trilobata means "three-lobed", and refers to the leaves of the species.
Description Malus trilobata is a medium-sized deciduous tree. It initially assumes a narrow, upright habit with horizontal or ascending branching, but becomes more rounded with age. The species usually attains a mature size of or up to height by width. The leaves are deeply 3-lobed, with each lobe usually again divided into several pointed lobes, so that the leaf may almost appear palmate. In leaf shape, the species resembles certain species of maple (Acer), as well as the wild service-tree (Aria torminalis). The leaves are glossy and smooth (glabrous) above, bright green and hairy (pubescent) below, especially on the veins. They are rather stiff and slightly wider ( than long (, turning from orange to red to deep purple in fall. The branchlets are initially densely pubescent, but become smooth quickly.
The tree blooms relatively late — usually between May and June — bearing large flowers with white petals and up to in diameter, with flowers appearing in loose umbels of up to 10. The petals narrow abruptly towards the ovary, creating a rounded space between them. The apple fruits ripen in fall, between October and November. They are roundish and large, being around in diameter and weighing around . Yellow in colour, they are edible and reportedly have a good taste. The pulp has grit cells, which is otherwise atypical of apples, but common in pears. The seeds are dark and around in diameter. The bark of the tree is dark grey, deeply fissured and scaly with age. The species develops a deep root system, and is noted to be drought-resistant. M. trilobata is a long-lived species, with 350-450 years age estimated for old specimens in Isparta and Antalya, Turkey.
M. trilobata is diploid, with a chromosome number of 2n=34.
Distribution and ecology
Malus trilobata is distributed in mountainous terrain in the eastern Mediterranean, however, its range is remarkably disjunct, consisting of several disconnected populations. In the European part of its range, the species has been recorded down to altitude, but it has also been observed at and on Şaphane Mountain and Mount Lebanon, respectively. M. trilobata is not endemic to Lebanon, despite claims to the contrary.
In Europe, M. trilobata is known from Thrace, specifically Evros Prefecture in Greece and the eastern Rhodopes in Bulgaria. Here, it occurs between in xero-thermophilous communities on acidic siliceous soil, together with deciduous oaks (pubescent oak Quercus pubescens, valonia oak Q. ithaburensis subsp. macrolepis, Hungarian oak Q. frainetto) and Turkish pine (Pinus brutia), fellow Rosaceae (wild service-tree Aria torminalis, sorb tree Cormus domestica, almond-leaved pear Pyrus spinosa), mock privet (Phillyrea latifolia), Greek strawberry tree (Arbutus andrachne), oriental hornbeam (Carpinus orientalis), flowering ash (Fraxinus ornus), terebinth (Pistacia terebinthus), tanner's sumach (Rhus coriaria), Eastern prickly juniper (Juniperus deltoides), garland thorn (Paliurus spina-christi), bladder-senna (Colutea arborescens), black bryony (Dioscorea communis), pink rock-rose (Cistus creticus), wild asparagus (Asparagus acutifolius) and traveller's joy (Clematis vitalba).