Plicosepalus acaciae (Zucc.) Wiens & Polhill
Loranthus acaciae Zucc., Tapinostemma acaciae (Zucc.) Tiegh.
Eng.: Acacia strap flower
Semi-parasitic woody plant with long and intricate branches up to 1-2(3) m long, unarmed. Through special organs, it parasitizes the branches of the trees and shrubs on which it lives (haustoria), from which it obtains water and minerals but performs photosynthesis with its own leaves. Sometimes it forms large subspherical tangles of up to 1-2 m or even more on the branches of the trees it parasitizes. Twigs glabrous. Leaves 3-7.5 × 0.5-3 cm, oblong-lanceolate to oblong-elliptic, sometimes obovate, slightly curved, obliquely cuneate, glabrous, coriaceous, green or slightly glaucous, with 3-5 longitudinal nerves, entire, opposite, subaltern or alternate; petiole 3-10 mm. Inflorescences with 1-2(4) pedunculated umbels, each with 1-2 flowers, pentameric, zygomorphic and pedicelate. Corolla linear (2.5)3-4.5 cm long, curved, with petals welded together in the lower half, bright red, orange or yellowish in color. Stamens 5, subequal, curved like the petals. The fruit is an oblong-ellipsoid berry of c. 1.2 × 1 cm, greenish at first, then red, which the birds eat, digest the fleshy part and then deposit the seed on the branches of the host trees, where they begin to germinate and take root.
Flowering:
from June to April of the following year, during these 10 months some plants flower twice, others present more or less flowers during that entire period.
Fruiting:
from late summer to late spring of the following year.
Habitat:
Branches of trees and shrubs in dry areas, semidesert and even desert zones. In North Africa mainly along wadis and depressions in the terrain where there is greater edaphic moisture.
Distribution:
NE Africa, the Middle East, and the Arabian Peninsula. In N Africa, it is found in Chad (Ennedi), Sudan, Eritrea, Ethiopia, Djibouti and Somalia, outside Africa in Sinai, Palestine, Israel and the Arabian peninsula.
Observations:
This species parasitizes several species of plants, some from saline environments such as those of the genera Atriplex or Tamarix. But its name comes from the fact that it appears and shows its greatest development generally on the species of the genus Vachellia (formerly Acacia). The seeds are dispersed by a single species of bird, the white-spectacled bulbul Pycnonotus xanthopygos, which deposits them on branches covered in a sticky substance, so they do not fall off. Another important bird species in the life cycle of this plant is the orange-tufted sunbird Nectarinia osea, but not as a seed distributor, in this case it is as a pollinator.
Conservation status:
A rare species in North Africa, little is known about its conservation status. Currently, it is not assessed at a global level on the IUCN Red List of Threatened Species.
