Is Holosteum glutinosum (M. Bieb.) Fisch. et C. A. Mey. (Caryophyllaceae: Alsinoideae) just a subtaxon of H. umbellatum L. or a distinct species?

2020

Turczaninowia, Vol 23, Iss 4, Pp 50-64 (2020)

The genus Holosteum L. distributed mostly in temperate Eurasia has very confused taxonomy. Modern estimation of the species richness varies from one species worldwide to seven species occurring just in Eastern Europe. One of the most problematic species of the genus is H. glutinosum(M. Bieb.) Fisch. et C. A. Mey. usually treated as a subspecies or a variety of H. umbellatum L. On the base of extensive study of the protologues, type material, a rich variety of other herbarium specimens, photos of all relevant taxa, and living plants in the field we recognize H. glutinosum as a distinct species. This species has three characters unique in the genus Holosteum: pure green color of leaves and sepals, completely herbaceous bracts, and lanceolate leaves; additional diagnostic characters are 10 stamens, dense glandular pilosity of leaves, sepals, bracts, stem, and pedicels, and entire petals longer than sepals. The species also has statistically significant differences from H. umbellatum (longer leaves, longer and wider petals, and longer capsule) while occurring in sympatry with it. Two subspecies are recognized within H. glutinosum: H. glutinosum subsp. glutinosumdistributed in Caspian Depression, Transcaucasia, Western and Middle Asia, and H. glutinosum subsp. liniflorum Fateryga, nom. et stat. nov. (≡ H. liniflorum Steven ex Fisch. et C. A. Mey. 1840 [non 1837], nom. illeg.), presumably endemic to the Crimea. The lectotypes are designated for the latter name and also for H. glandulosum Bertol., H. umbellatum var. pleiandrum Fenzl, H. imberbe J. Gay, nom. illeg. superfl., H. imberbe var. brachypetalum J. Gay, and H. imberbe var. macropetalum J. Gay. Reports of H. glutinosum from most European countries (other than Russia) are considered to be erroneous due to numerous misidentifications in herbaria and incorrect synonymy (e. g., with H. heuffelii Wierzb., which is actually conspecific with H. umbellatum). A key to the species and subspecies is provided; a total of six taxa are recognized in the genus: H. breistrofferi Greuter et Charpin, H. glutinosum subsp. glutinosum, H. glutinosum subsp. liniflorum, H. marginatum C. A. Mey., H. tenerrimum Boiss., and H. umbellatum.

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Altay State University, 2020.

distribution, lectotype, nomenclature, systematics, taxonomy, typification, Botany, QK1-989