Orobanche ingens (Beck) Tzvelev (1990: 182)

Piwowarczyk, Renata, Pedraja, Óscar Sánchez, Khutsishvili, Manana & Kharazishvili, Davit, 2023, Holoparasitic Orobanchaceae in Georgia (Caucasus): taxonomic revision, diversity, distribution, habitats and host range, Phytotaxa 604 (1), pp. 1-103 : 75-77

16. Orobanche ingens (Beck) Tzvelev (1990: 182)

. TYPE:— DAGESTAN (lectotype designated by Tzvelev (1990: 182) [with its clarification by Piwowarczyk et al. 2022: 57], distr. Kasi-Kumukh, ad viam inter pagos Chelussun et Kumukh, 6400–7000 ft., 13 VII 1897, № 10524, Th. Alexeenko (LE01015386!). Basionym:— O. alba f. ingens Beck (1922: 38 [470]). Heterotypic synonyms:— O. alsatica var. heraclei Tzvelev (1957: 591) , nom. inval. ( Turland et al. 2018: Art. 39.1); O. alsatica var. heraclei Tzvelev in Novopokrovsky & Tzvelev (1958. 111), nom. inval. ( Tzvelev 2015: 211, nom. nud. [sic]). Misapplied names:— O. alba var. bidentata sensu Beck in Engler (1930: 155) [saltem p.p.], non O. alba f. bidentata Beck (1890: 211) . Fig. 50 .

General distribution: — The Caucasus, mostly the Greater Caucasus range, Russia (Krasnodar Krai, Karachay-Cherkessia, North Ossetia, Dagestan), and Georgia. Needs confirmation in Azerbaijan. Endemic to the Caucasus (after Piwowarczyk et al. 2022) .

Distribution: —In the northern parts, Racha-Lechkhumi and Kvemo Svaneti prov. ( Fig. 51 ).

Habitat: —In Georgia in tall herbaceous habitats, mainly in subalpine meadows, edges of forests and shrublands, forest glades, usually 2000–2300 m.

Hosts: —Parasitises Heracleum species (Apiaceae) in the Caucasus Mountains ( Tzvelev 2015). It cannot be ruled out as a parasite also on others large Apiaceae species. In Georgia on Heracleum leskovii Grossh. , but probably also on Ligusticum alatum (M. Bieb.) Spreng. (= Cnidiocarpa alata (M. Bieb.) Pimenov & Kljuykov ), but this needs confirmation (observed by R. Piwowarczyk in Georgia, but root attachment could not be verified due to the density of associated species) ( Piwowarczyk et al. 2022).

Phenology: —Flowering (June) July–August, fruiting (July) August (September).

Conservation status: —Critically Endangered (CR) – B 1 ab (iii) + 2 ab (iii). Only one locality is known in Georgia. EOO is less than 100 km 2 and AOO is less than 10 km 2. At the discovered site, the species is threatened by the progressive overgrowing of the forest glade. However, the population is numerous, with several hundred individuals, and the species still requires further research regarding its distribution.

Taxonomic note: —The species was mistakenly described as a form of O. alba (subsect. Glandulosae), on the basis of a part of the materials collected by Th. Alexeenko in Dagestan ( Beck 1922: 38), and next Tzvelev (1990, 2015) continued to indicate its relationship with O. alsatica aggr., especially with O. bartlingii Griseb. (subsect. Curvatae). However, according to morphological features, it belongs to the subsect. Minores / Speciosae (see also a table with distinctive morphological characteristics with similar species in Piwowarczyk et al. 2022).

Specimens examined: — GEORGIA. Racha-Lechkhumi and Kvemo Svaneti prov.: tall herbaceous vegetation, forest edges and glade, near the trail to Udziro lake , 1.5–2 km S of Shovi village, 42°41’07’’N, 43°39’56’’E, 2050– 2100 m, 18 July 2018, R. Piwowarczyk ( KTC) .

Figures

FIGURE 50. Orobanche ingens. A–D, L. General habit. E–G. Flower, side view. H–J. Flower, front view. K–M. Represenative hosts (K. Heracleum leskovii. L–M. Ligusticum alatum). N. Representative habitat (Racha-Lechkhumi and Kvemo Svaneti prov., S of Shovi, near the trail to Udziro Lake). Photos by R. Piwowarczyk.

FIGURE 51. Distribution of Orobanche ingens in Georgia.