A new species of the genus Amberboa (Asteraceae) from Dagestan

A new species of the genus Amberboa (Asteraceae) from Dagestan is described, which was previously mixed with A. glauca. The new species differs from the latter in the large size of capitula, marginal flowers, achenes, and longer pappus. In addition, the color of the corolla in the described species is dark pink, while in A. glauca it is light pink. Amberboa daghestanica also differs in almost glabrous involucres and longer (up to 10 mm) receptacle pellicles, while A. glauca has involucres with tomentose-arachnoid pubescence, and receptacle pellicles about 4–5 mm long. The area of the new species covers the limestone mid-mountain Dagestan, while A. glauca occurs only in the lower foothills. The differences between the new species and A. moschata, a species from Southern Transcaucasia, are also shown.

In the first edition of "Flora of the Caucasus" (Grossheim, 1934) and in "Key to Plants of the Caucasus" (Grossheim, 1949), two species were indicated for Dagestan: A. glauca and A. biennis Iljin.By the first species A. Grossheim meant taxon now called A. moschata (L.) DC.As it turned out later, this taxon is distributed only in the Southern Transcaucasia, namely in the Ararat Valley and in adjacent areas of Turkey (Gabrielyan, 2008).The characters of the second taxon (A.biennis) correspond to the true A. glauca distributed more widely from Dagestan to North-East Turkey.In "Flora of the USSR" N. Tzvelev (1963) distinguished these taxa correctly, but due to the impossibility of studying the type material, some points remained questionable and not fully clarified.Thus, in this work, N. Tzvelev wrote in a note to A. glauca: "In Dagestan, and apparently also in Transcaucasia, along roads and near human settlements, there are specimens of A. glauca with slightly enlarged marginal flowers, deviating to the previous species (A.moschata -author's note), but quite well different from it" (Tzvelev, 1963: 327).
Observations of this taxon in nature in Dagestan revealed an interesting picture.It turned out that all populations of this taxon within the Intramountain Limestone Dagestan are quite well isolated and differ from the foothill populations.This circumstance prompted more detailed population studies of this species in different parts of its distribution area.
To clarify the differences, qualitative and quantitative morphological characters, as well as features of ecology and biology, were studied.For this purpose, two populations were selected in the foothill and mid-mountain zones of Dagestan.A brief description of the natural conditions of these populations is given in Table 1.In each population, 30 plants were selected for the study, in which the diameter of the capitula, the size of the marginal flowers, the length of the achene and pappus, as well as the nature of the pubescence and the color of the corolla were studied.The results of studying these characters are shown in Table 2.
As can be seen in Table 2, almost all indicators of the studied quantitative characters in populations from the mid-mountain zone (i.e., A. daghestanica) are higher compared to populations from the foothill zone (A.glauca).The difference is especially visible in the size of the marginal flowers.Thus, the average values of this character for populations from the foothills are about 2.5 cm, while in populations from the middle mountains, the length of the marginal flowers is about 3.8 cm, that is, the marginal flowers of A. daghestanica are 1.5 cm longer than those of A. glauca (Fig. 1).
Significant differences between foothill and midmountain populations are also observed in the size of achenes (Table 2, Fig. 2).On average, the length of achenes in plants from the foothill populations (A.glauca) is about 3.5 mm, while in populations from the mid-mountain zone, it is approximately 4 mm (A.daghestanica).
Greater difference between the compared populations is noticeable in the size of the pappus.Thus, in plants from the foothill populations (A.glauca), the length of the pappus ranges from 1.84 to 1.95 mm, while in plants from the mid-mountain populations (A.daghestanica), it is almost twice as long and ranges from 3.54 to 3.71 mm.In addition, the thickness of the achenes in plants from the midmountain zone reaches 1.5 mm, while the achenes in plants from the foothill populations are about 1 mm thick, and they are more intensely pubescent.It is worth noting a significant difference between the compared populations in the length of the receptacle pellicles.The size of the pellicles in plants from the foothill populations (A.glauca) reaches only 5 mm, while in plants from the mid-mountain zone (A.daghestanica), the receptacle pellicles are twice as long and are about 8-10 mm.
The compared populations also differ in some qualitative characters.The marginal flowers of plants from the mid-mountain zone are more intensely colored (pink, sometimes dark pink) compared to plants from the foothill zone, whose marginal flowers are light pink.In addition, during the flowering period, the involucre of plants from the foothill populations (A.glauca) has intense tomentose-arachnoid pubescence, while in plants from the populations from the mid-mountain zone (A.daghestanica), it is completely glabrous or sometimes covered with sparse pubescence, especially the lower leaflets of the involucre.
A discriminant analysis based on the studied quantitative characters (diameter of capitula, length of marginal flowers, length of achene and length of pappus) showed that the mid-mountain populations were quite well separated from the foothill populations (Fig. 3).In the Figure 3 we can see the characters of foothill populations slightly more scattered while the characters of populations from the midmountain zone are more grouped.At the same time, the populations of the foothill and mid-mountain zones are quite well separated and do not overlap.The results obtained give us a reason to distinguish plants from the mid-mountain Dagestan into an independent species, which differs well in morphological characters from plants in the foothill zone and has a well-defined isolated distribution area.A description of this taxon is provided below.Amberboa daghestanica Murtazaliev, sp.nov.Biennial plant, up to 70(90) cm high.Taproot thick, sometimes thickened to 2 cm in diameter.Stems erect, simple or branched, covered with short curly hairs, ribbed.The leaves mostly pinnately divided or pinnately dissected, sometimes the upper ones with entire margins, the basal and lower stem ones petiolate, the rest sessile (Fig. 4).
Leaves pubescent with curly hairs, especially along the margins and veins; the pubescence sparse on the underside.Medium stem leaves up to 10-15 cm long.Capitula large, single, at the ends of leafless long peduncles.Involucres large, spherical or ovoidspherical: up to 15 mm long and up to 20 mm wide; pubescence weak, often absent.Involucre bracts often with a pinkish membranous margin approximately 1 mm wide.Affinity.The new species is closest to A. glauca, from which it differs in the large size of the capitula, longer marginal flowers, large seeds and pappus, darker color of the corolla and less pubescence of the involucre (Table 2).Amberboa moschata differs from the described species in the smaller size and shape of the marginal flowers (in A. daghestanica the marginal flowers are broadly infundibular).The marginal flowers of A. moschata are divided into only 1/5 of the expanded part by 10-20 teeth, whereas in A. daghestanica they are divided almost to half by 15-25 teeth (Fig. 6).Amberboa moschata is found only in the Ararat Valley and surrounding areas of Turkey.
Distribution.The area of Amberboa daghestanica is geographically well isolated.The species is found exclusively in the limestone part of mid-mountain Dagestan, while A. glauca is found only in the lower foothills (Fig. 7).Endemic to Dagestan.
Ecology and biology features.The new species grows in communities of mountain xerophytes in the limestone part of Dagestan at altitudes of 500-1500 m a. s. l., preferring exposed and steep slopes without dense vegetation.Often it is found on clayey slopes, on the sides along roads, as well as in human settlements.Rarely it grows in communities of upland beard grass steppes (Fig. 8).Flowering from late May to August, sometimes secondary flowering in early autumn, fruiting in July.
slight pubescence at base of involucre Sparse pubescence at base of involucre A new species of the genus Amberboa (Asteraceae) from Dagestan

Fig. 3 .
Fig. 3. Distribution of the population characters in the space of two canonical roots according to the results of discriminant analysis.

Table 1
Characteristic of natural conditions of the studied populations Amberboa