Flora-Fauna

Cuscuta planiflora Ten.

(Fl. Napol. 3: 250; 1828 – Nouvelle Flore du Liban et de la Syrie, vol. 2, Pl. CCXL nº 1; 1969)

• Life-form & habit: Annual leafless parasitic herb with slender, filiform, yellow to orange stems, 0.2–0.5 mm thick, twining over host plants. Haustoria numerous, penetrating the host tissues to absorb nutrients. Plant forms dense tangles on various shrubs and herbs.

• Leaves: Reduced to minute, triangular or ovate scales, 0.3–0.5 mm long, translucent and sessile.

• Inflorescence & flowers: Small, sessile or shortly pedicellate clusters of 3–10 flowers, forming compact, often glomerulate cymes. Calyx hemispheric, 4–5-lobed, lobes ovate, obtuse. Corolla campanulate to rotate, 2–3 mm wide, white to cream, lobes short, broadly triangular. Stamens 5, inserted near the base of the corolla lobes; scales small, truncate, slightly fringed, placed halfway up the tube. Styles 2, short, free or slightly united at the base; stigmas capitate.

• Fruit: Capsule globose, slightly depressed at the apex, circumscissile (opening transversely), 2–3 mm in diameter; seeds 4, ovoid, brown, smooth to faintly rugulose.

• Phenology: Flowers and fruits from April to August, depending on altitude and host availability.

• Habitat & elevation: Parasitic on a wide range of annual and perennial hosts, especially in dry fields, roadsides, and open scrub, from sea level to 1 500 m; prefers sunny, disturbed habitats on calcareous or sandy soils.

• Lebanese distribution: Recorded by Mouterde from various regions of Mount Lebanon and the Beqaa — notably Zahlé, Barouk, Dahr el-Baïdar, and Ras Baalbeck; parasitic on Medicago, Heliotropium, and Salsola species in steppe and open scrubland.

• Doubtfully present in: East Aegean Is.

• Native to: Afghanistan, Albania, Algeria, Angola, Baleares, Bulgaria, Canary Is., Cape Verde, Chad, Corse, Cyprus, Egypt, Eritrea, Ethiopia, France, Greece, Gulf States, India, Iran, Iraq, Italy, Kenya, Kriti, Krym, Lebanon-Syria, Libya, Madagascar, Madeira, Morocco, Namibia, Northern Provinces, NW. Balkan Pen., Oman, Palestine, Portugal, Romania, Rwanda, Sardegna, Saudi Arabia, Sicilia, Sinai, Socotra, Somalia, Spain, Sudan-South Sudan, Tanzania, Transcaucasus, Tunisia, Türkiye, Uganda, West Himalaya, Yemen, Zambia, Zimbabwe (POWO).

• Introduced into: Germany, South Australia, Victoria, Western Australia (POWO).

• ⚠️ Taxonomic note: A highly adaptable parasitic species distinguished by its compact glomerulate inflorescences, short, campanulate corolla, and circumscissile capsule. It parasitises a wide range of herbaceous and shrubby hosts, often dominating disturbed dry habitats. Sometimes confused with Cuscuta campestris Yunck., but the latter has a more cylindrical corolla and non-circumscissile capsules. In the Levant, C. planiflora is the most widespread lowland Cuscuta species.