Family composed of about 158 genera and 2000 species of trees, shrubs, lianas (rarely) and herbaceous plants, with an almost cosmopolitan distribution, but with an important representation in the tropics and the Irano-Turanian and Mediterranean regions. In temperate regions, the various genera are composed of annual or perennial herbaceous species. In the tropics, there are trees and shrubs species. In North Africa, in the transition between the Mediterranean and tropical regions, there are some trees, shrubs and perennials with ± woody stems (genera Cordia, Euploca and Trichodesma) and several subshrubs smaller than 50 cm in height (genus Echiochilon).
In the genus Euploca Nutt., composed for the most part of herbaceous species, there is one woody species, E. rariflora (Stocks) Diane & Hilger (Heliotropium rariflorum Stocks), of up to 0.5(0.8) m in height, with upright greyish branches, the older branches covered in a whitish-silvery bark that peels off in strips, exposing a dark brown (almost black) bark underneath, that also peels off; young branchlets green, with white applied hairs. Leaves 7-25(35) × 1-5 mm, linear or linear-lanceolate, with a somewhat revolute margin and covered in white applied and scattered hairs (barely touching each other); petiole c. 2 mm. Inflorescence sparse, spiciform, with white applied hairs, pentamerous flowers; calyx with subequal lobes, lanceolate; corolla 2.4-3 mm, white or greenish-yellowish. Nutlet subglobose, covered with erect hairs. Its distribution is mainly Saharo-Sindian, from the Atlantic Sahara to the NW of India, reaching towards the SE up to Tanzania. In North Africa it is distributed through the southern and western Sahara.
Also belonging to this family are the subshrubs from the genus Echiochilon Desf., with stems and branches woody but barely reaching 40(50) cm in height. Bark whitish, fissured and peeling off into longitudinal plates; branchlets and leaves with scattered applied white hairs (clearly revealing the green colour of the leaf); leaves from lanceolate to oblong, fleshy, 0-5-1.5 cm. The North African species with most lignified stems are: E. fruticosum Desf. is the most widespread species in the Sahara, from the Atlantic Ocean to the Red Sea; it is distinguished by its corolla, hairy on its outer face. E. chazaliei (Cham.) I.M.Johnst., from western Sahara (from Mauritania to S of Morocco) has a corolla that is glabrous on its outer face. E. simonneaui Dubuis & Faurel, is an endemic of the western Sahara (Saguia el Hamra); leaves lanceolate with hairs only along the margin and corolla glabrous on the outside. Finally, E. kotschyi (Boiss. & Hohen.) I.M.Johnst. differs by its white petals with yellowish base; found in the Arabian Peninsula and Iran, but also cited in Libya.
Currently, none oft hese species have been assessed at a global level in the IUCN Red List of Threatened Species.
Key to genera
1 Tree or shrub up to 5(10) m in height Cordia
1 Evergreen plant, slightly lignified or, when lignified, generally shorter than 0.5 m 2
2 Plant with stems slighly or not lignified. Leaves with numerous small, white and rigid spines on almost the entire surface Trichodesma
2 Subshrub with woody stems. Leaves with white hairs but not spiny 3
3 Leaves linear. Corolla white or greenish-yellow Euploca
3 Leaves lanceolate or oblong. Corolla blueish or white-reddish Echiochilon
Updated by: A.J. Mendoza, F.J. Pérez García & J. Charco.