Introduction
Beta L. (Amaranthaceae Juss. sensu APGIV 2016) comprises 10 species naturally distributed in most parts of Europe, N-Africa, SW-Asia, and India, whereas some taxa occur as aliens in central and N-Europe, tropical and S-Africa, central and E-Asia, SE-Australia, and the Americas (POWO, 2026); the number of subspecies or varieties, which are mainly included in the high variable B. vulgaris L. s.l., still remains undefined (Kadereit et al., 2006; Uotila, 2011).
Recently, Iamonico (2019) proposed a classification of the subfam. Betoideae Ulbr. by distinguishing two tribes [Beteae (Moq.) Kadereit & al. and Halbitzieae Ulb.]. Tribe Betae was further divided into three sections, i.e. Beta, Corollinae (Tranzschel) Ulb., and Macrocarpae Iamonico. Subsections were also considered, i.e. subsect. Beta and subsect. Patulae Iamonico (under sect. Beta), and subsect. Corollinae and subsect. Nanae (Ulb.) Iamonico (under sect. Corollinae).
Avetisyan et al. (2022), based on collections in Gegharkunik Province (Armenia), proposed to describe a new natural Beta hybrid (“Beta × intermedium”) using morphological and molecular data. Despite the authors given both the parent species names (B. corolliflora Zosimov and B. macrorhiza Stevens) and, more or less scattered throughout the text, a description of the hybrid, no type (holo-) was reported. As a consequence, according to the Arts. 40.1 and 40.7 of the International Code of Nomenclature for algae, fungi, and plants (Madrid Code; Turland et al., 2025) and Turland et al. (2020), the hybrid name resulted as not validly published. Here we here validate this new hybrid by a formal description and type indication.
Material and methods
The work is based on both analysis of pertinent literature (cited throughout the text) and the examination of specimens preserved at the herbarium YAI (acronym according to Thiers, 2026 [continuously update]).
Taxonomic treatment
Beta × vardenyatensis Aloyan & Iamonico, hybr. nov. (Beta corolliflora × Beta macrorhiza).
Holotype. Armenia. Gegharkunik Province: Vardenyats Mountain Pass, near the road to the Orbelian’s Caravanserai, 2410 m a.s.l., 39°56′17"N, 45°13′54"E, 12 July 2019, Aloyan & Harutyunyan s.n. (YAI751!).
Diagnosis. Beta × vardenyatensis differs from B. macrorhiza by stem height (about 90 cm vs. about 40 cm in B. macrorhiza), size of the leaf blades [13–15(−16) × (2.0–)2.8–5.2(−6.0) cm vs. 13.9–16.1 × 4.3–6.7 cm in B. macrorhiza], length of the petiole [(7–)8–10 cm vs. 4.3–6.7 cm in B. macrorhiza)], diameter and colour of roots (about 8 cm and red vs. about 12 cm and white in B. macrorhiza). From B. corolliflora, the new hybrid differs in having petioles longer [(7.0–)8.0–10.0 cm in B. × vardenyatensis vs. 4.3–6.7 cm in B. corolliflora) and root diameter (about 8 cm in B. × vardenyatensis vs. 8–15 cm in B. corolliflora).
Description. Perennial herb, with a woody, cylindrical (about 8 cm in diameter) red root. Stem erect-ascending angular, about 90 cm tall. Leaves alternate, petiolate (lower ones) or sessile (upper), entire, ovate to lanceolate [13–15(−16) × (2.0–)2.8–5.2(−6.0) cm], smooth; petioles (7–)8–10 cm long. Inflorescences in elongate panicle-like glomerules; bracts leaflike. Flowers perfect, bisexual with cup-shaped perianth; tepals 5, whitish to yellowish-greenish, flat. Fruits (achenes) including a few seeds.
Etymology. The epithet vardenyatensis is dedicated to the location in Armenia where the new hybrid was found.
Proposed vernacular name. Vardenyats beet (English); Vardenyats Chakndegh (Armenian).
Distribution and habitat. Beta × vardenyatensis is currently known only from locus classicus (Vardenyats Mountain Pass, Gegharkunik Province, E-Armenia) where inhabits at 2410 m a.s.l. with Cephalaria gigantea (Ledeb.) Bobrov, Trifolium ambiguum M.Bieb., Medicago sativa L. subsp. sativa, Plantago lanceolata L., Artemisia absinthium L., Campanula grandiflora Jacq., and Cichorium intybus L.
Conservation status. We prefer to avoid the IUCN assessment of Beta × vardenyatensis since further localities for this taxon could be found. As a consequence, B. × vardenyatensis is to be considered as DD (Deficient Data) according to the IUCN (2024) categories.
Taxonomic notes. Beta × vardenyatensis belongs to Beta sect. Corollinae subsect. Corollinae where both the parents (B. corolliflora and B. macrorhiza) are included (Iamonico, 2019).
Other specimens. Beta corolliflora: ARMENIA. Kotayk province: Hrazdan region (40°23′335″N, 44°39′57″E), 1675 m a.s.l., 20 July 2019, Aloyan & Harutyunyan s.n. (YAI22!). Beta macrorhiza: ARMENIA. Gegharkunik province: Vardenyats Mountain Pass, around the Orbelian’s Caravanserai (39°55′56″N, 45°14′00″E), 2410 m a.s.l., 12 July 2019, Aloyan & Harutyunyan s.n. (YAI26!).
Acknowledgements
Thanks are due to the staff of the herbarium YAI for the support.