Family |
Ericaceae
Rhododendron ponticum subsp. ponticum
Boiss.
Rhododendron ponticum subsp. ponticum L.
(Sp. Pl.: 392; 1753 – syn. Rhododendron ponticum var. brachycarpum Boiss., Fl. Orient. 3: 971; 1875 – Nouvelle Flore du Liban et de la Syrie, vol. 2, Pl. CCXV nº 3; 1969)
• Life-form & habit: Evergreen shrub or small tree, 2–6 m tall, with spreading or ascending branches forming dense thickets. Young twigs pubescent, later glabrescent, reddish-brown, and smooth.
• Leaves: Alternate, leathery, oblong to elliptic, 8–18 × 2–5 cm, entire, glabrous and glossy dark green above, paler beneath with scattered brownish hairs along the midrib; petiole 5–10 mm. Persistent for several years, giving the plant a dense evergreen aspect.
• Inflorescence & flowers: Terminal corymbs of 8–20 funnel-shaped flowers, 25–35 mm long. Corolla lilac to deep purplish-pink with a darker blotch on the upper lobe; lobes 5, rounded. Calyx minute, 5-toothed; stamens 10, unequal, exserted; style slender, slightly longer than the corolla.
• Fruit: Capsule ovoid, 10–15 mm long, pubescent, dehiscing into five valves; seeds numerous, minute, brown, and narrowly winged.
• Phenology: Flowers from April to June; fruits ripen in autumn.
• Habitat & elevation: Humid montane forests, ravines, and shaded stream margins, 1 200–2 000 m. Prefers acidic or siliceous soils, under Abies cilicica, Fagus orientalis, or Quercus cerris, often in persistently moist, shaded habitats.
• Lebanese distribution: Rare and very localised, known from Ehden, Bcharreh, Tannourine, and Hadeth el-Jebbé in northern Mount Lebanon. Considered by Mouterde (1969) as a relict species of the humid montane flora.
• Native to: Bulgaria, Lebanon-Syria, North Caucasus, Transcaucasus, Türkiye, Türkiye-in-Europe (POWO).
• Introduced into: Belgium, France, Germany, Madeira, Myanmar, Netherlands (POWO).
• ⚠️ Taxonomic note: The Lebanese plant described by Boissier (1875) as Rhododendron ponticum var. brachycarpum is now included within R. ponticum subsp. ponticum L. according to Plants of the World Online (POWO).
Mouterde (1969) considered these Lebanese stands as genuine wild populations, representing the southernmost natural range of the species, restricted to humid, north-facing valleys of Mount Lebanon. It is distinguished by compact inflorescences, shorter capsules, and adaptation to cooler, shaded habitats—an ecological relict of postglacial floristic connections between the Levant and the Caucasus.