Lathyrus libani

Lathyrus libani
Scientific classification
Kingdom:	Plantae
Clade:	Embryophytes
Clade:	Tracheophytes
Clade:	Spermatophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Fabales
Family:	Fabaceae
Subfamily:	Faboideae
Genus:	Lathyrus
Species:	L. libani
Binomial name
Lathyrus libani Fritsch
Synonyms
Orobus grandiflorus Boiss. (1872) Lathyrus macranthus Voss (1894) Lathyrus laevigatus subsp. libani (Fritsch) Breistr. (1940) Lathyrus laevigatus subsp. grandiflorus (Boiss.) Hendrych (1959)

Lathyrus libani, the Lebanon vetchling, is a perennial herb in the family Fabaceae (subfamily Faboideae), belonging to the genus Lathyrus L., a large assemblage of climbing and scrambling legumes commonly known as vetchlings and peavines.¹ It was first described by the Austrian botanist Karl Fritsch in 1895, and takes its specific epithet from Lebanon, within whose mountain ranges the species was first documented.² The species is native to the mountains of southern Turkey, Syria, and Lebanon, where it inhabits montane woodlands and cedar forests between approximately 1,200 and 1,800 meters above sea level.³⁴

Lathyrus libani was formally described by Karl Fritsch (1864–1934), a professor of systematic botany at the University of Graz and director of its botanical garden, in a paper published in 1895 in the Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Classe.² The species had previously been treated as Orobus grandiflorus by Pierre Edmond Boissier in his Flora Orientalis (1872), but as that name was a later homonym of the earlier Lathyrus grandiflorus Sibth. & Sm., Fritsch's new combination under the name libani became the accepted name.¹³ Plants of the World Online (POWO), maintained by the Royal Botanic Gardens, Kew, accepts Lathyrus libani Fritsch as a valid species and lists four synonyms: Orobus grandiflorus Boiss. (1872), Lathyrus macranthus Voss (1894), Lathyrus laevigatus subsp. libani (Fritsch) Breistr. (1940), and Lathyrus laevigatus subsp. grandiflorus (Boiss.) Hendrych (1959).¹

The genus Lathyrus L. was established by Carl Linnaeus in his Species Plantarum of 1753 and currently comprises approximately 160 accepted species distributed through temperate regions of Europe, Asia, the Americas, and tropical East Africa.⁵ The generic name derives from the Ancient Greek láthuros (λάθυρος), an ancient term for a legume or pulse, recorded in Theophrastus and cited in Liddell and Scott's Greek–English Lexicon.⁶ The specific epithet libani is a Latin genitive of Libanus, the classical Latin name for Mount Lebanon, indicating the geographic origin of the type material.²

The authoritative floristic treatment for the Levantine range of the species is provided in volume two of Paul Mouterde's Nouvelle Flore du Liban et de la Syrie (1970), which records the species under the synonymy Orobus grandiflorus Boiss. and provides the most detailed morphological description available for populations in Lebanon and Syria.³

Lathyrus libani is a perennial herb with angular, erect stems growing 20–80 cm tall, glabrous except for a very light pubescence on young parts and a permanent slight villosity on the peduncles, pedicels, and petiolules.³ The leaves bear 3–4 (occasionally 5) pairs of petiolulate leaflets that are distant, broad, up to 8 × 4 cm, with well-marked pinnate venation and an obtuse or subacute apex. The stipules are semi-sagittate, oblong, acuminate, and finely denticulate at the base.³ The inflorescence is a raceme of 2–5 flowers borne on peduncles shorter than the subtending leaf. The calyx is glabrous to finely pubescent, with triangular teeth, the lower ones lanceolate and equaling or exceeding the tube. The corolla measures 1.5–2 cm and is white, turning brownish upon drying; the wings are slightly shorter than the keel.³ The fruit is a linear, glabrous pod at maturity, gradually attenuate at the apex.³ Flowering occurs in May and June.³

Lathyrus libani is native to Lebanon, Syria, and southern Turkey.¹⁷ Within Lebanon, confirmed localities include the environs of Ehden, the forest of Ehden, and the cedar forests of Bcharré. In Syria, the species has been recorded from the coastal mountains including Bois du Bassit and Slenfé, and from cedar forests of 'Aïn Zehalta.³ The species grows in montane woodlands and cedar forests at elevations of approximately 1,200–1,800 meters.³ A broader elevation range of 750 metres (2,460 ft) to 1,650 metres (5,410 ft) has been recorded across the species' distribution, encompassing populations in southern Turkey.⁴⁸ Lebanon is recognized as a biodiversity meso-hotspot within the Levant, with a vascular plant flora of significant richness relative to its small land area. A 2025 systematic review of the endemic flora identified 169 taxa belonging to 37 families and 99 genera, with Fabaceae constituting 11.2% of the endemic-rich families.⁹ The cedar forests and montane woodland habitats of northern Lebanon, within which L. libani is recorded, represent one of the most botanically significant landscape types remaining in the country.⁹

No formal assessment has been published for Lathyrus libani on the IUCN Red List of Threatened Species.¹⁰ The species' association with cedar forest and montane woodland habitats places it within ecosystems that have experienced significant reduction in Lebanon and Syria due to logging, land conversion, overgrazing, and prolonged conflict.⁹