THE GENUS SCOLYMUS TOURN. EX L. (ASTERACEAE): TAXONOMY AND DISTRIBUTION

VÁZQUEZ, F.M. (2000) The genus Scolymus Tourn. ex L. (Asteraceae): taxonomy and distribution. Anales Jard. Bot. Madrid5i(\): 83-100. A taxonomic study of the genus Scolymus Tourn. ex L. is presented. Seven taxa are recognised, two of them new to science: Scolymus hispanicus subsp. occidentalis F.M. Vázquez, subsp. nov., and S. hispanicus [subsp. hispanicus] i. decoloratus Fiori ex F.M. Vázquez,/ nov.; a new combination, S. hispanicus [subsp. hispanicus] var. aggregatus (Ruch.) F.M. Vázquez, comb. & stat. nov., is proposed. The type and full synonymy for each taxon are given. A selection of the specimens studied is presented in Appendix I. Some of the taxa are illustrated in figures.


INTRODUCTION
The species of Scolymus L. differ from the rest of the taxa in the Asteraceae by the Scolymus Tourn.ex L., Sp.Pl. 2: 813 presence of ligulate flowers and by having (1753) [Gen.PL, ed. 5: 355 (1754)] is dorsally compressed achenes which are included in the tribe Lactuceae Less., and it surrounded by the paleae.Some have a is integrated by three species and several pappus with two tofive stiff scabrous bristles.infraspecific taxa.Their distribution is by The objective of this paper is to revise the the Mediterranean, Macaronesian and Near taxonomy of the genus Scolymus Tourn.ex L., Orient áreas.
study the infraspecific variations, verify the distribution of each taxon and check the available names (choosing a lectotype when necessary).

MATERIAL AND METHODS
An extensive bibliographic search of the genus has been carried out.The catalogue of available names has been completed and all names, when possible, have been typified.
Description.Spiny annuals, biennials or perennials.Stems with spiny wings, simple or many ramified.Leaves alternate, pinnatifid, spiny-dentate, with prominent veins, scabrous to tomentose in the veins and glabrous to pubescent in the limb; margins with yellow prominent veins.Capitula sessile, ligulate, axillary or terminal, with involucral leaves, assembled in spike-like or raceme-like panicle.Involucre with many bracts in several rows, the upper herbaceous and longer than the lower, all very alike, membranous.Receptacle conical and somewhat short or elongate, paleaceous; paleae ovate, enclosing achenes.Ligules yellow to orange or white.Achenes dorsally compressed, the lower longer than the upper, enclosed in receptacular scales (paleae).Pappus absent or of 2 to 5 stiff scabrous bristles.One of these plates has been selected here as type of the name S. paniculatus Ucria.
Morphology.The characters of S. maculatus are very constant.Variations exist in the size of the stem and the floral pieces as a consequence of living in different habitats.In calcareous areas, with high temperatures in summer and scarce precipitation, the specimens are usually small, while in humid areas and in places with mild temperatures, they are usually higher.In the places where 5. maculatus and 5. hispanicus grow together no hybrid was found hybrid.

Distribution. South of Mediterranean
Observations.The typification of S. congestus Lam. is difficult, because the lack of an adequate material in the P-LAM herbarium and the fact that LAMARK (1779) mentions only one synonym: Scolymus theophrasti Tournef.480.In TOURNEFORT (1700), next to Scolymus Chrysanthemos, annus A.R. Par.III., we found the name Scolymus Theophrasti Narbonensis Clus.Hist, cliij.and this should be the name mentioned in the protologue.
In the P-LAM herbarium at Paris there is a sheet of S. hispanicus L. with a hand-written note by Lamarck naming it Scolymus theophrasti hispanicus Clus.hist.In the work by CLUSIO (1601) two clearly different taxa exists: S. theophrasti hispanicus, with only a capitulum in each involucral leave and little ramified inflorescence (CLUSIO, 1601, p. 153, drawing 1) and S. theophrasti narbonensis, with 2-3 capitula in each involucral leaf and very ramified inflorescence ( CLUSIO, 1601, p. 153, drawing 2).The material conserved in P-LAM makes reference to the plant described by CLUSIO (1601) with only a capitulum in the involucral leaves and with few lateral branches.But in the description of S. congestus Lam.we read: "...; elle est aussi tres-rameuse,... On trouve quelques fleurs solitaires, mais la plupart sont ramasse"es par paquets de trois ou quatre ensemble."and those characters point to the material described by CLUSIO (1601) with 2-3 capitula in each involucral leaf and with numerous lateral branches.Having this in mind, the material conserved in P-LAM can not be the type of the name 5. congestus Lam.We know that Lamarck had used the well known work by CLUSIO (1601) and don't know whether Lamarck had directly studied some specimens of Scolymus in the Tournefort herbarium or not.The only possibility we have for a S. congestus Lam.type would be looking for it in CLUSIO (1601).Consequently I have selected the drawing on page 153 as lectotype.
Morphology.In S. hispanicus there are four varieties based on the disposition of the floral organs, dimensions of the leaves and characteristic of the achenes.
The general inflorescence in S. hispanicus may be of two types: a spike-like paniculate inflorescence and in paniculate inflorescence.The plants with spike-like inflorescences have few ramifications and their capitula are grouped 1-3 in the axil of the fertile leaves.The plants with a paniculate inflorescence have numerous ramifications and their capitulum are grouped 2-5 in the axil of the fertile leaves.
The plants with a spike-like inflorescence are elongate, while the plants with a paniculate inflorescence are globose.Moreover, the plants with a paniculate inflorescence have a smaller receptacle and smaller achenes than the plants with spike-like inflorescences (see table 1).
These features, congruent with the chorological information, have been used to taxonomically separate two groups of individuals: those of elongate appearance from those of globose appearance.
In the group of specimens with elongate appearance we found also variations in the achene morphology, ligule and basal leaves size.The plants in the coast populations have all the achenes with three or more bristle, while the plants in the inland populations have some achenes with only two bristles.Coastal specimens have their capitula in groups of 1-3, while inland specimens usually have only a capitulum in each involucral leave.The plants in the coastal populations present leaves and ligules longer than the plants in the inland populations (see table 1).Finally, the plants from Algeria and Morocco coastal populations have leaves and ligules bigger than the plants in the rest of the coastal populations of the Mediterranean basin.
Based on this, four groups have been established in S. hispanicus:   The four infraspecific taxa recognised have a more or less different distribution.However, the area of each one overlap with the area of the others.We have assigned the subspecific rank to the group of elongate appearance and capitula solitary because it has a more clearly differentiated geographical distribution than the rest of the groups.Only on the coasts of South Spain and France and in the depression of Florence (Italy) is it possible to see, growing in the same habitat, populations of subsp.occidentalis and subsp.hispanicus.In this situation it is frequent to find specimens with intermediate characters.They may be hybrids.

General distribution. South of
Ecology.The populations of var.hispanicus live in compact and clayey soils, with an acid or basic pH.This variety endures high thermic contrasts in areas with more than 20 days of frost a year.The var. hispanicus lives in the basin of the Mediterranean area from sea level to an altitude of 1200 m, together with Onopordum spp., Carduus spp., Carthamus spp., Sylibum spp, etc.
Observations.This taxon had been recognised previously by some pre-Linnaean authors such as DODOENS (1583) 20)25-37(44) mm, yellow to orange.Achenes 3.5-5.5(6.5)mm.Pappus of three to seven bristles in central achenes, otherwise three to five.Flowering May to July.
Morphology.In the Algeria populations of S. grandiflorus Desf. it is possible to find specimens with the bracts of the involucre very pubescent and with shorts appendices, but this variation isn't considered worthy of taxonomic recognition in this paper.
Ecology.This species usually lives in coastal areas, on sandy soils.It is a wasteland plant, that cohabits with Carduus spp., Carthamus spp., Onopordum spp., etc.
Distribution.S. grandiflorus Desf.has a wide distribution in the Mediterranean basin.However, it is more frequent to find this species in the Northwest of Africa coasts and in Sicily.In the rest of its area of distribution it appears forming small populations without continuity.Moreover, the absence of this species in the east of the Iberian Peninsula and Balearic Island and in the south of the Balkan Peninsula is note worthy.South of Mediterranean Region: Algeria, Libya, Morocco, Tunisia.North of Mediterranean: France, Italy, Turkey.East of Mediterranean: Lebanon.Mediterranean Islands: Malta, Sardinia, Sicilia (Appendix 1.3).