Flora-Fauna

Erodium trichomanifolium L’Hér.

(Geraniologia: 3; 1802 – Nouvelle Flore du Liban et de la Syrie, vol. 2, Pl. CLXXXIX nº 2; 1969)

• Life-form & habit: Perennial herb forming dense mats or cushions up to 10–25 cm across, with a woody taproot and numerous short flowering stems. Stems villous, prostrate to ascending, branching from the base and covered with short, soft hairs.

• Leaves: All basal or sub-basal, forming compact rosettes; blades pinnatisect, 3–8 cm long, segments oblong to linear, densely grey-pubescent, giving a silvery or ashy-green appearance. Petioles short, erect or ascending, hairy throughout.

• Inflorescence & flowers: Peduncles 5–15 cm tall, 2–5-flowered. Sepals lanceolate, 4–5 mm long, hairy and often tinged reddish. Petals 5, obovate, 8–10 mm, pale lilac, pink, or white, slightly notched at apex, with darker veins near the base. Stamens 5 fertile and 5 reduced; anthers yellow.

• Fruit: Schizocarp with 5 mericarps, each with a smooth, reticulate body and a long, spirally coiling awn 25–35 mm; beak densely hairy.

• Phenology: Flowers from April to July; fruits mature from June to August.

• Habitat & elevation: Rocky limestone slopes, montane meadows, and open steppe grasslands, typically between 1 400 and 2 800 m; prefers sunny, well-drained, calcareous habitats.

• Lebanese distribution: Common in high mountains of Mount Lebanon — notably the slopes of Sannine, Makmel, and Barouk; recorded by Mouterde and confirmed by recent field observations across the central and northern Lebanese ranges.

• Native to: Endemic to Lebanon.

• ⚠️ Taxonomic note: Although Plants of the World Online lists this species as native to Lebanon, Syria, and Türkiye, Allan Robinson’s 2022 investigation has conclusively shown that Erodium trichomanifolium is endemic to Lebanon, and that earlier reports from neighbouring regions were due to misidentifications. His research clarifies the long-standing confusion dating back to Boissier’s 19th-century writings, which erroneously stated that this species occurred both in Spain and Lebanon. This claim caused decades of taxonomic uncertainty and led to horticultural misuses of the name.

Robinson notes that Boissier had, in fact, mistaken Erodium cheilanthifolium for E. trichomanifolium in Spain. Both species were named for their fern-like foliage — after Cheilanthes and Trichomanes — but only E. trichomanifolium truly belongs to the Lebanese flora. He further documents that plants sold in nurseries under this name are usually hybrids of Spanish origin, later circulated as Erodium ‘Katherine Joy’.

Paul Mouterde, in his Nouvelle Flore du Liban et de la Syrie, recognised a white-flowered high-altitude form, which he called subsp. albiflorum. Photographic records by Ramy Maalouf (florafauna.life) confirm its occurrence in situ across Lebanon’s high mountains.
Moreover, although Professor Guittonneau once suggested synonymy with Erodium amanum, Allan Robinson’s comparison of Farrer’s description and field observations clearly distinguishes the two, establishing E. trichomanifolium as a true Lebanese endemic.

Plants are dimorphic, with separate male and female individuals — a trait consistent with other Levantine Erodium species. It represents one of the most distinctive alpine endemics of Lebanon’s limestone summits.