﻿Phelypaeaboissierif.lutea (Orobanchaceae), a peculiar new form from Turkey and typification of the name of this species

﻿Abstract The genus Phelypaea includes three holoparasite species with one of the most intense red flowers among all plants worldwide. So far, there are few references to other colour taxa of this genus. We describe a new yellow-coloured form, Phelypaeaboissierif.lutea, from Hakkari province in the Cilo Mountains of SE Turkey, found at an altitude of 2,470 m. In typical P.boissieri, here typified by us, the flowers are deeply red, and stems, calyx and scales are red to brown, or rarely pale-brown, whereas in the entire population of f.lutea the corolla, calyx, and scales are yellow to orange with black folds in the corolla, while only the stem is brownish.

Species from the genus Phelypaea are achlorophyllous and possess one of the most intense red flowers among all plants worldwide. A recent study on P. tournefortii showed that anthocyanins were found in unprecedented large quantities in the flowers, as well as large amounts of polyphenols, especially eukovoside (Piwowarczyk et al. 2020).
So far, there have been few references to colour forms other than red in the genus Phelypaea in the literature. One of them is P. coccinea f. aurantiaca Beck in Engl., Pflanzenr. 96: 261 (1930), which was described from Karabakh in the Caucasus based on material collected by Radde as having an orange corolla ("aurantiaco"). Another non-red colour form is P. helenae Popl., described from Alushta in Crimea ("corolla orange-yellow") and, according to Novopokrovsky and Tzvelev (1958: 28), it is synonymous with the species mentioned before and does not constitute a different species (but rather a case of polychromism) with regard to P. coccinea ("corolla bright-red"), and both yellow and red forms occur together in Crimea. In P. coccinea, sometimes the corolla in the lower-side is orangish or yellow, with the upper side in the typical red color preserved (Piwowarczyk et al. 2019). Within one population, there may be individuals with a corolla which is red on both sides, as well as with one yellow-orange side.
In this paper, we typify P. boissieri and indicate its synonyms, and besides, describe a new yellowish-coloured form from Turkey.

Typification of Phelypaea boissieri
Phelypaea boissieri (Reut.) Stapf in Bull. Misc. Inform. Kew 1915, 6: 291 (1915[17 Aug 1915   and Caria by Pinard (Reuter 1847: 42). Later, Boissier (1879: 494) included it within his Anoplanthus coccineus, which would be the origin of future confusions between the two species. In addition, he described two new varieties, the var. peduncularis (P. tournefortii Desf.) and the var. nigrovittatus (P. boissieri (Reut.) Stapf ). Stapf (1915) raised the variety of Reuter to the rank of species and clarified the differences between the three taxa, so that nowadays we believe that they form this genus. Beck (1930), in a monograph on the family, preferred to continue treating our species with the rank of var. within P. coccinea, but created some confusion when giving the distribution of this species where he included the var. described by Reuter. Finally, Cullen (2010) complements the description of P. boissieri, giving good illustrations with analysis, providing a new key for the three species, and indicating the distribution of the species treated here.

A new form of Phelypaea boissieri
Phelypaea boissieri f. lutea Ü. Subasi, R. Piwowarczyk, Ó. Sánchez Pedraja, f. nov. Figure 3 Diagnosis. This new taxon is very similar to typical Phelypaea boissieri, and is compliant with morphometric characteristics in the description of the plant after Reuter (1847: 42, sub Anoplanthus biebersteinii var. boissieri), Stapf (1915), Nicolson (1975), Cullen (2010) but differs significantly in color and, usually, a higher stem. In typical P. boissieri, flowers are deeply red, and stem, calyx and scales are red to brown, or rarely pale-brown, whereas in the f. lutea corolla, calyx, and scales are yellow to orange with black folds in the corolla, with only the stem being brownish (Fig. 3).
Distribution and ecology. This taxon is known exclusively from the type locality. The Cilo (Glacial) Mountains (Cilo (Buzul) Dağı) are part of the Hakkâri Dağları range and include the third highest peak of Turkey with an altitude of 4,135 meters. Turkey's Eastern Anatolia Region, the easternmost extension of the Southeast Taurus Mountains, is located within the borders of Hakkari province. The locality of P. boissieri f. lutea is located in Hakkari province, Kırıkdağ village, Gümüşlü location (Kurdish: Spixane). This area is located around Mt Uludoruk (Reşko 4,135 m), at an altitude of approximately 2,470 meters. In this area dominated by high mountain steppe plants, the bedrock consists mainly of tectonic deposits and limestone. It is approximately 20 km from any settlements. Parasitising Centaurea, probably C. persica Boiss. (new host-plant). Phenology -flowering end of June to July, fruiting July to August. The population size is small, over a dozen individuals. The number of individuals counted in the area is fewer than 100. The entire population in this locality is formed by higher plants than the type with yellow corolla. In the future, research into the cause, phytochemical composition, ecological importance and adaptation, and also into pollinators of typical red Phelypaea individuals and yellow-orange ones could shed new light on this topic.
Etymology. The form name originated from the yellow to orange colouring of plants.