Launaea arborescens (Batt.) Murb.

Mannheimer, Coleen, 2023, First record of the North African Launaea arborescens in southern Africa, Bothalia (a 7) 53 (1), pp. 1-10 : 3

Launaea arborescens (Batt.) Murb. (adapted from Kilian 1997)

Dense, intricate, spinescent, irregularly hemispherical shrub, usually up to 1 m high, almost leafless ( Figures 2 and 3 ). Branches terete, divaricately and intricately branched, with distinct joints and spinescent terminal segments; young branches stiff, green, smooth, waxy, becoming greyish brown with age. Latex whitish with unpleasant smell. Leaves clustered at the bases of the lower branches, somewhat succulent, blue-green, mostly narrowly spathulate to linear in outline, soon deciduous, higher up the shoots reduced to inconspicuous, ovate-acute bracts. Capitulae (‘flowers’) bright yellow, up to 16 mm in diameter, always terminal and single on the peduncles, which persist as spines after shedding of the capitulae. Capitula with 7–19 florets (‘petals’), each with five ‘teeth’ at the tip. Involucre up to 15 mm long, cylindrical to conical. Achenes with 5 main ribs accompanied by 2 secondary ribs, with transverse, roundish, and tuberculate wrinkles, often somewhat powdery-papillose, brown. Pappus 5–8 mm long, comprising numerous white, setaceous rays.

A specimen (Antje Burke AB20007) was deposited at the National Botanical Research Institute in Windhoek, which is the first record of the plant in southern Africa.

Figures

Figure 2. Launaea arborescens in the Kuiseb Delta; A, flower; B, leaves; C, general habitat with Wortel nursery in background; D, plant in habitat. Photographs: A, C. Mannheimer; B–D, A. Burke.

Figure 3. Launaea arborescens in the Kuiseb Delta near Walvis Bay. Photograph: A. Burke.