Viola henriquesii (Willk. ex Coutinho, 1892) W. Becker, 1906

Magrini, Sara & Scoppola, Anna, 2015, Further studies in Viola Sect. Melanium (Violaceae). Identity and typification of Viola nana and V. henriquesii, two neglected European Atlantic taxa, Phytotaxa 230 (3), pp. 259-266 : 261

Viola henriquesii

The name Viola tricolor L. var. henriquesii Willk. ex Coutinho (1892: 36) was published by Coutinho, who reported Willkomm’s description of a new Viola species (in litt.) with small, blue flowers from Coimbra, Beira Littoral ( Portugal): “ « Nana , gracillima, caule filiformi erecto, simplici vel parum ramoso, foliis rotundatis grosse crenatis, basi saepe subreniformibus, infirmis longe, summis breviter petiolatis, stipulis parvis folio multo brevioribus, basi indivisis, lobo terminali oblongo-lineari, lateralibus majore, integerrimo; floribus longissime pedunculatis, pedunculo erecto filiformi sub apice curvato bracteolam linearem minutam gerente; flore parvulo coerulascente, petalis rotundatis, impari subemarginato, calcare saccato obtuso subincurvo intense caeruleo, appendicibus calicinis duplo longiore. Caules 1–10 cm. longi, basi saepe arcuato-adscendentes, pedunculi 3–4,5 cm. longi, foliorum limbus 3–8 mm. diametro latus, flores 7 mm. longi. Tota planta laete virens, parce puberula. » Wk. In speciminibus majoribus folia superiora elliptica vel oblongo-elliptica. Stipulae, ut vidimus, saepissime foliis consimiles: inferiorae indivisae ad segmentum medium reductae, superiorae basi pauce et brevissime palmatifidae!”.

Since its publication, this taxon has undergone several rank changes. It was regarded as a species by Willkomm, but published as a variety of V. tricolor by Coutinho (1892: 36), who afterward elevated it to sub-specific rank ( Coutinho 1913: 419). Subsequently, it was considered as a variety of V. arvensis by Becker (1904: 46), who later elevated it to the rank of species ( Becker 1906: 190), and, finally brought it back again to variety-rank, but of another species, V. kitaibeliana ( Becker 1910: 94) .

Currently, even though Muñoz Garmendia et al. (1993) reported V. tricolor subsp. henriquesii in V. kitaibeliana s.l. for the Iberian Peninsula, many Spanish and Portuguese authors prefer to retain Becker’s name, V. kitaibeliana var. henriquesii , which refers to a narrow endemic taxon limited to Beira Littoral ( Portugal) and to the Galician coasts ( Spain) where it is considered as an indicator species of the endemic association Violo henriquesii-Silenetum littoreae Izco & Guitián ( Izco et al. 1988) of grey dunes ( Lomba et al. 2008, Costa et al. 2011, 2012). Furthemore, Aldasoro (1992) determined chromosome number 2n = 40 for plants with blue flowers from the Galician-Portuguese Sector of the Iberian Peninsula, collected “ En torno a Coimbra ” (Beira Littoral, Portugal) (MA 507003! and MA 508284!) in “ una colonia de lo que se publicó inicialmente como V. tricolor var. vel subsp. henriquesii Coutinho ” ( Aldasoro & Laínz 1992) and along the Galician maritime sands, in the Isla de Arousa (MA 508285!) and near O Grove (MA 508286!) (Pontevedra, Spain), where V. kitaibeliana var. henriquesii had been reported ( Izco & al. 1988). This last taxon has a high ecological and chorological specificity: early spring annual grasslands of the inner slope of mobile dunes and grassland clearings of grey dunes (Violo henriquesii-Silenetum littoreae Izco & Guitián 1988; habitat 2230 Malcolmietalia dune grasslands, European Commission 2013), and a narrow distribution area that results to be limited to the Atlantic coast of the Northwest Iberian Peninsula, the Galician-Portuguese sector, which is mainly characterised by a Temperate hyperoceanic submediterranean bioclimate ( Izco et al. 1988, Rivas-Martínez et al. 2004, Costa et al. 2011).

On the other hand, this taxon cannot be considered as a variety or a subspecies of either V. tricolor (2n = 26), V. arvensis (2n = 34) or V. kitaibeliana (2n = 16) because of its different chromosome number (2n = 40), the specificity of its habitat, and its narrow distribution area. Finally, we suggest recovering Willkomm’s epithet “ henriquesii ” for the pansy of the Galician-Portuguese Sector, but, for all these reasons, we propose to reaffirm this taxon as a distinct species saving Becker’s name V. henriquesii .