Taraxacum lateritium Dahlstedt (1906: 32)

Kirschner, Jan, Štěpánek, Jan & Buryy, Vladimir V., 2025, Towards a revision of Taraxacum sect. Borealia (Compositae, Crepidinae) in Siberia and the continental Far East, with special reference to the dandelions of the Altai and Kamchatka, Phytotaxa 679 (1), pp. 1-147 : 61-64

21. Taraxacum lateritium Dahlstedt (1906: 32)

Type:—[ RUSSIA, Chukotka] Arktiska Sibirien, Irkajpij, 68°55’ N, 179°28’ E, 12–15 Sep 1878, F. R. Kjellman s. n. ( S 13-4092 !, lectotype – 1st step typification: Tzvelev (1987b: 290); 2nd step typification: designated here by P. Efimov; isolectotype: S 13-4093 !). – Reise nach der Tschuktschen-Halbinsel, Behringsstrasse, “Snetke-ön” [correctly: Lütke Insel (Ostrov Litke), SE. Chukotka, ca. 65°37’29”N, 170°54’10”W], 11 Aug 1881, Au. Krause & Ar. Krause 123 ( B, residual syntype, not extant, but photo of the specimen and a sample of achenes preserved in S 13-4054 !, residual syntype). – [Chukotka] St. Lawrence Bay , 65°30’ N, 171°E, 20–21 Jul 1879, F. R. Kjellman s. n. ( S 13-4061 !, residual syntype).– Sibiria, Jenisei, “Mesemkin” [correctly: Mesenkin, right bank of Yenisei, at about 71°27’ N], 1875, A. N. Lundström ( S 13-4095 !, residual syntype, but see comments below) .

Etymology:—Dark brick red (achene colour).

Plants glabrous or subglabrous, slender, usually 10–17 (–25) cm tall. Petiole pale greenish or slightly purplish basally, narrow, unwinged, or very narrowly winged. Leaves linear-oblanceolate in outline, (4–) 5–12 (–17) × 0.8–1.5 (–2.0) cm, usually pinnatifid to pinnatipartite, with 3–4 (–5) pairs of ± patent, or patent-subrecurved, deltoid-triangular, or triangular, margins often dentate (rarely subentire), sometimes ± obtuse lateral segments; terminal segment triangular to elongated-triangular. Scapes typically sparsely arachnoid below capitulum, rarely subglabrous, overtopping leaves, rarely subequalling them. Capitulum yellow, small, ca. 1.5–2 cm wide. Involucre blackish green, 6–7 mm wide and narrowly rounded at base. Outer phyllaries ca. (9–) 11–14 (15), appressed, imbricate, or subimbricate, usually ovate-lanceolate, sometimes ovate or lanceolate, (4–) 5–6 (–8) × 2.0–2.5 (–2.8) mm, surface evenly dark black-green, rarely with a darker middle part, border absent or rarely very narrow and indistinct, to 0.1 mm wide, margin glabrous, apex with black, distinct cornicles or thick short horns; inner phyllaries ca. 11–13 mm long, usually dark corniculate or callose. Outer ligules faintly striped greyish outside. Stigmas dark discoloured. Pollen present, pollen grains irregular in size. Achenes pinkish grey-brown to reddish-brown, (4.3–) 4.5–5.2 × 1.0– 1.2 mm, body densely and shortly spinulose in upper 1/3–2/5, gradually narrowing in cylindrical to subcylindrical cone 0.5–0.9 × 0.25–0.30 mm; beak thin, 6–7.5 mm long; pappus ± white or yellowish white, 6.5–7 mm long. – Fig. 38 , 39 .

Notes on the typification, variation and identity:—We consider the original material of this species as taxonomically heterogeneous. It is represented by at least five herbarium specimens collected at four places, mostly from Chukotka, but one (S 13-4095) from a distant place in the region of lower Yenisei River, a site over 3500 km from Chukotka; some specific features of the latter specimen were pointed out in the protologue ( Dahlstedt 1906: 34), which was supported by Haglund (1946: 346), who treated it as “somewhat dubious”. The latter specimen was therefore excluded from our typification and interpretation considerations, as different taxonomically from the other syntypes.

The first lectotypification attempt was published by Haglund (1946: 328) who wrote: ... “just as in the type of T. lateritium (cf. Dahlstedt 1906, p. 18)”. Dahlstedt (1906: 43–44), in an explanation of figures on Plate 18, says [translated from Swedish]: “All figures after a specimen from Irkaipij, Arctic Siberia”. On the plate, achenes and variously divided or lobulate leaves belong to S 13-4092, while an undivided leaf and probably also the phyllaries were depicted according to S 13-4093. Haglund therefore, when speaking about “ type ”, referred to the whole gathering, F. R. Kjellman s. n. from 12–15 Sep 1878.

Another lectotypification was published by Doll (1973: 165):: “Typus: Holotypus im h S; Originalmaterial im h S (v.), Locus typicus: SU: Behringssund, Snetke-ön. 1881. Aurel & Krause” [sic!]. The problem of this typification is that Doll referred to a specimen not extant at that time (destroyed in B). Moreover, Haglund had already restricted the lectotype choice to the Irkaipij gathering. The same restriction was done by Tzvelev (1987b: 290).

We therefore asked P. Efimov of LE for the typification, and he follows the existing lectotypification of T. lateritium by a specimen from Irkaipij, considering it as a first step typification designating a gathering of two equal specimens with identical labels ( Tzvelev 1987b: 290); the larger and more representative specimen is used for the second step lectotypification in the present contribution. Importantly, specimens from Irkaipij were preferentially used for the description in the protologue ( Dahlstedt 1906: 34). In the protologue, however, the description bears a stamp of generalized picture which unites features of different specimens. In this respect, seed color is illustrative as it is described as dark red in mature condition, whereas ripe achenes from the lectotype specimen can be described only as slightly pinkish grey-brown or light brown with a red hue. It is quite possible that the color of ripe achenes in the protologue is described after another specimen, e.g. after one collected at Lütke Island, Chukotka (S 13-4054); its fruits show a distinct dark-red coloration. Such a difference in the color of ripe achenes between specimens makes evidence that at least a specimen from Lütke Island is taxonomically different, but its exact determination is problematic because only the achenes and a low-resolution photo are extant, and it had no flowers. The last residual syntype, a specimen from Saint-Lawrence bay, is also difficult to determine correctly, because it has no ripe achenes; regarding red hue of unripe fruits and distinctly imbricate phyllaries, it is supposed to be taxonomically identical with the lectotype specimen, representing rather small plants at an earlier ontogenetic stage.

Diagnostic notes:—The current understanding of T. lateritium in a narrow sense implies the following diagnostic characters: rather slender growth (but substantially more robust than in species of T. sect. Arctica), leaves variable, usually pinnatilobed to pinnatipartite, outer phyllaries dark-green, ± unbordered, more or less imbricate, with little horns, pollen present, achenes rather distinctly spinulose, with red pigment, but not dark red when mature.A counterpart of T. lateritium with seeds without purple pigment is T. macilentum ; both taxa seem to be rather similar and may be closely related to each other. T. macilentum can be also distinguished from T. lateritium by its usually distinctly winged petioles, and larger horns. Surprisingly, the majority of specimens preserved in LE under the name of T. lateritium belong to a species of T. sect. Arctica, T. korjakorum Kharkevich & Tzvelev (1978: 840) . While in the leaf shape T. korjakorum approaches T. lateritium , it is readily distinguished by the broadly bordered outer phyllaries, dark red-brown achenes and the absence of pollen.

Distribution:—The literature reported T. lateritium as a common species in the Arctics ( Schischkin 1964; Krasnikov 1997; Tzvelev 1987b), possibly combining several taxa under this name, which share an important common feature, i.e. red pigment on the achenes; supposedly, this material as a whole might belong not only to T. sect. Borealia but, in part, also to T. sect. Arctica. In reality, the occurrence of T. lateritium was documented from Chukotka, including its westernmost parts, from the mountains of the Magadan Region and Kamchatka, from islands in the Bering Sea, and from the northwestern Alaska ( Haglund 1946: 346, fig. 9). Taraxacum lateritium belongs to the few dandelions with an amphi-Beringian distribution.

Specimens examined:—[ RUSSIA.] Eastern Chukotka, northern coast, vicinity of Nutepel’men, station of Polyarnaya , 3 Aug 1969, A. A . Nechaev & T. V . Plieva ( LE 1229529 ). – West Chukotka, Anyuy Range , Rau-Chu River basin, upper Erguveem River , 11 Jul 1967, E. V . Zimarskaya , A. A . Korobkov & B. A . Yurtsev ( LE 1229528 ). – Eastern Chukotka, northern coast, vicinity of Nutepel’men , a sandy spit, 12 Aug 1969, A. A . Nechaev & T. V . Plieva ( LE 1229530 ). – Southern part of the Magadan Region, N . coast of Sea of Okhotsk , S . slopes of Mt. [?] Skamnitaya , ca. 1400 m, 24 Jul 1989, V. V . Yakubov ( KAM, no. det. 36907). – Central Kamchatka, Mil’kovskyy District , township of Nikolka , ca 1560 m, mountain tundra, 21 Aug 1987, V. V . Yakubov ( KAM, no. det. 36908) . – [ USA, Alaska] Bering Sea, St. Lawrence Island, Sevoonga , Jul–Aug 1931, O. W . Geist ( US 1789495!). – Bering Strait, Little Diomede Island , 65°46’ N, 168°55’ W, 14–20 Aug 1926, A. E . Porsild & R. T . Porsild 1730 ( CAN 10165052 !) .

Figures

FIGURE 38. Taraxacum lateritium. Details of involucre (A, S 13-4093; B, C, S 13-4061). Scale bars = 5 mm.

FIGURE 39. Taraxacum lateritium. General habit (LE 1229529).