Kilian, N.: Lactuca stebbinsii (Lactuceae, Compositae), a puzzling new species from Angola. — Willdenowia 31: 71–78. 2001. — ISSN 0511-9618.
A small perennial herb from marshy meadows in the highlands of SW Angola, only known from three 19th and early 20th century collections, is described as Lactuca stebbinsii, a species new to science, and illustrated. The taxonomic position of the unusual species with entirely beakless, apically truncate, pale brown, distinctly compressed and glabrous achenes within the Lactuca-Prenanthes line of the Lactucinae is discussed. The morphological features indicate a placement in Lactuca s.l. as the most plausible solution. Possible relationships are discussed but cannot be established yet.