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Español. Se presenta la revisión taxonómica del género Helminthotheca Vaill., basada en el estudio morfológico de material en toda su área de distribución. El género, que se incluye en la subtribu Hypochaeridinae de la tribu Cichorieae, tiene una distribución centrada principalmente en el oeste de la Región Mediterránea, y se diferencia del resto de los géneros de la subtribu por la presencia de acúleos ± espinosos y setas gloquidiadas en los tallos, hojas y a veces en las brácteas del involucro, pero sobre todo por la presencia de 5 hojas involucrantes que rodean al verdadero involucro del capítulo. Sobre la base del ciclo de vida, la morfología de las hojas involucrantes y los tipos de frutos, las distintas especies del género se reagrupan en tres secciones: Helminthotheca, Vigineixia y Eliptica. Las secciones Helminthotheca y Vigineixia, ambas monotípicas, comprenden especies anuales, con hojas involucrantes cordiformes y los frutos del capítulo dimorfos. La sección Eliptica, con 5 especies reconocidas, se diferencia de las otras secciones por incluir especies perennes, con hojas involucrantes ovadas o elípticas y frutos del capítulo homomorfos. En este trabajo se efectúa una combinación nueva, Helminthotheca sect. Vigineixia (Pomel) Talavera, y se da un nombre nuevo a Picris subgen. Deckera sensu Battandier: Helminthotheca sect. Eliptica Talavera & Tremetsberger. La sección Eliptica es la más compleja debido, sobre todo, a la hibridación interespecífica cuando las especies conviven, habiéndose detectado zonas híbridas en el N del Guadalquivir al W de Sierra Morena (S de España), en el extremo más occidental de las montañas del Rif, cerca de la Península Tingitana, en el E del Rif (NW of Marruecos), en las montañas del Atlas argelino y en las colinas arcillosas de Beni-Zenthis (Orán, Argelia).English. Based on a morphological study, we present the revision of the genus Helminthotheca Vaill., a small member of the subtribe Hypochaeridinae of the tribe Cichorieae, which is mainly distributed in the western part of the Mediterranean region. Helminthotheca is differentiated from the remaining genera of the subtribe by the presence of ± spiny prickles and glochid-like bristles in stems, leaves and, sometimes, involucral bracts. The main distinguishing character, however, is the presence of 5 outer involucral leaves, which surround the proper involucre of the head. Based on the life cycle, the morphology of the outer involucral leaves and the fruit types found in the head, species of Helminthotheca are rearranged in three sections: Helminthotheca, Vigineixia and Eliptica. The sections Helminthotheca and Vigineixia, both monotypic, are annuals with cordate outer involucral leaves and dimorphic fruits in the head. The section Eliptica, with five recognized species, is differentiated from the other sections by its perennial habit, ovate or elliptic outer involucral leaves and homomorphic fruits in the head. Here, we make a new combination, Helminthotheca sect. Vigineixia (Pomel) Talavera, and give a new name to Picris subgen. Deckera sensu Battandier, Helminthotheca sect. Eliptica Talavera & Tremetsberger. The section Eliptica is the most complex section, due mainly to interspecific hybridization between all species, when they co-occur, with hybrid zones having been detected in the N of the Guadalquivir River in the W of the Sierra Morena (S Spain), in the westernmost part of the Rif Mountains, near the Tangier Peninsula, in the E Rif and Middle Atlas (NW Morocco), in the Algerian Atlas Mountains and in the argillaceous hills of Beni-Zenthis (Oran, Algeria).

Phylogeography above the species level is a powerful tool for investigating patterns and processes at the boundary between divergent and reticulate relationships. We examined the evolutionary history of perennial species in the western Mediterranean composite genus Helminthotheca using DNA sequence and fingerprint data. The origin of the group was in western North Africa, a region of intensive Pleistocene speciation. From here it expanded to the Iberian Peninsula and Sicily. The inferred evolutionary history is compatible with the concept of ecogeographic isolation, which refers to the fact that geographic ranges of diverging lineages are largely non-overlapping due to adaptive differentiation., In phylogeography, DNA sequence and fingerprint data at the population level are used to infer evolutionary histories of species. Phylogeography above the species level is concerned with the genealogical aspects of divergent lineages. Here, we present a phylogeographic study to examine the evolutionary history of a western Mediterranean composite, focusing on the perennial species of Helminthotheca (Asteraceae, Cichorieae). We used molecular markers (amplified fragment length polymorphism (AFLP), internal transcribed spacer and plastid DNA sequences) to infer relationships among populations throughout the distributional range of the group. Interpretation is aided by biogeographic and molecular clock analyses. Four coherent entities are revealed by Bayesian mixture clustering of AFLP data, which correspond to taxa previously recognized at the rank of subspecies. The origin of the group was in western North Africa, from where it expanded across the Strait of Gibraltar to the Iberian Peninsula and across the Strait of Sicily to Sicily. Pleistocene lineage divergence is inferred within western North Africa as well as within the western Iberian region. The existence of the four entities as discrete evolutionary lineages suggests that they should be elevated to the rank of species, yielding H. aculeata, H. comosa, H. maroccana and H. spinosa, whereby the latter two necessitate new combinations.

Johann Gottfried Zinn's Catalogus Plantarum Horti Academici et Agri Gottingensis conscriptus (1757), although a work of pre-Linnaean character as regards its specific nomenclature, nevertheless gave valid publication to a number of pre-Linnaean generic names which Linnaeus had ignored or suppressed in 1753, as pointed out by Sprague (1) and Dandy (2). The attention of the present author, working on a revision of the genus Picris L. (3,4), has been focused upon the name Helminthotheca, for which Zinn's entry is as follows