(2003)  Page(s) 138.  
 
According to our observations in the fiels and in the herbaria....Paeonia in the Caucasus may be classified clearly into three major groups as follows:
1 Roots fusiformly thickened; leaflets/segments of lower leaves more than 70 in number, narrow-lanceolate to filiform, less than 1.5 cm wide
2 Leaflets/segments of lower leaves with segments less than 100 in number, narrow-lanceolate ......1 Intermedia group.
2 Leaflets/segments of lower leaves more than 130 in number, linear to filiform..... 2 Tenuifolia group.
2 Roots carrot-shaped; leaflets of lower leaves mostly 9, rarely 10-19; leaflets ovate, oblong or obovate, over 3 cm wide......3 Daurica group.

(2003)  Page(s) 138.  Includes photo(s).
 
TENUIFOLIA This group includes P. tenuifolia L., P. biebersteiniana Rupr. and P. carthalinica N. Ketzch. The first was described from Ukraine, the second from Stavropol in north Caucasus (Russia), and the third from Kartli, Georgia.
....We visited Temnolesskaya, south of Stavropol, Russia, the type locality of P. biebersteiniana. We found a huge population there stretching over hundreds of metres on sloping meadows. Two population samples were taken at an interval of about 500 m.... All plants possessed fusiform roots, biternate leaves with 134–340 segments and red flowers, but varied in colour of filaments, colour and number of carpels, and width of leaf segments. Filament colour varied widely from yellowish white, pink below and red above, to totally red; carpels were one, two or three in number, all tomentose, with hair colour green or red (Figs 1–3); the width of leaf segments varied from 1.2 to 4.3 mm. Sixty-seven herbarium specimens in LE from the Ukraine and north Caucasus were measured; P. biebersteiniana varies from 0.5 to 6.0 mm.

(2003)  Page(s) 143-144.  
 
Paeonia tenuifolia Linnaeus, SP. Pl. ed. 2. 748. 1762;....Paeonia biebersteiniana Ruprecht in Mem. Acad. Imper. Sci. St.-Petersb. Ser. 7. 15(2) (Fl. Caucas.): 47. 1869;...Paeonia tenuifolia var. biebersteiniana (Rupr.) Busch, Fl. Caucas. Crit. 3(3): 9 et 224. 1901; .....Paeonia carthalinica N. Ketzchoweli in Notul. Syst. ac Geogr. Inst. Bot. Thbil., 21: 18. 1958;.....Perennials with roots consistently fusiform-thickened. Leaves biternate, leaflets fine-segmented, with >130 segments, segments varying from 0. 5 to 6 mm in width, glabrous on both sides, rarely with sparse bristles along veins on the upper surface. Flowers consistently red; bracts and sepals green, green but purple-red at periphery to totally purple-red; filaments entirely yellowish white, pink below but yellowish white above to entirely purple-red; carpels 1–3, consistently tomentose, hairs green, yellow to totally purple; stigmata red. ....The species is distributed in Bulgaria, Yugoslavia, Romania, south-west Russia and Ukraine. Within the Caucasus, it is mainly found in the northern part of the region; Azerbaijan and Georgia each have only one locality. It grows in meadows, sparse bushes and sparse woods. It is confined to below 800 m, and flowers from late April to early June, 2n = 10.

(2003)  Page(s) 137.  
 
Georgia: Kartli, Igoeti, 630 m Sandstones, S. slope, sparse bushes and grasses...P. tenuifolia

Georgia: Kartli, Mukhrani, near Village Dampalo, 760 m S. slope, river terrace, sparse bushes and young trees...The type locality of P. carthalinica (= P. tenuifolia)

Russia: Stavropol, 630 m Gentle S. slope, sloping meadows,....The type locality of P. biebersteiniana (= P. tenuifolia), and P. tenuifolia