Lathyrus turcicus Hamzaoğlu, 2023

Hamzaoğlu, Ergin, 2023, Lathyrus turcicus (Fabeae, Fabaceae), a new species from Northwestern Türkiye, Phytotaxa 598 (1), pp. 105-110 : 106-109

Lathyrus turcicus Hamzaoğlu , sp. nov. ( Figs. 1 and 2 , Table 1 ).

Type:— TÜRKİYE. Bursa: Büyükorhan, west of Durhasan village , near dam, forest clearings, rocky slopes, 900 m a.s.l., 31 August 2022, E.Hamzaoğlu 8048 (holotype GAZI!, isotypes GAZI!, ANK!, HUB!) .

Diagnosis:— Lathyrus turcicus is related to L. pallescens (1841: 723) It differs from L. pallescens , mainly by stipules shorter than petiole (not longer than petiole); the calyces are glabrous (not hairy); the calyx teeth subequal (not unequal); the standards and wings are almost equal and 13.2–15.3 mm long (not 20–24 mm); the keels 11–13 mm long (not 16–18 mm) and the legumes 7–9 mm wide (not 3–5 mm).

Description:—Erect to ascending, glabrous, perennial with ramified rhizomes. Stems not winged, angled, ribbed, 25–50 cm. Leaves pinnate, with 5–7 mm petiolate and 2–4 mm aristate; leaflets subopposite to opposite, 5-parallel-veined from base; leaflets on lower leaves 2–3-paired, linear, 25–80 × 3–5 mm; leaflets on middle leaves 2–3-paired, linear, 20–60 × 1.5–3.5 mm; leaflets on upper leaves 1–2-paired, linear, 15–50 × 0.8–1.7 mm; stipules semi-sagittate, subulate, shorter than petiole. Peduncles 16–42 mm, as long as or longer than leaves, laxly 3–8-flowered; pedicels 2–5 mm. Calyx 5.7–7.2 mm, glabrous; tube gibbosus, 3.5–5 mm long, 5-veined; teeth subequal, 1.5–2.1 mm long, shorter than tube, broadly triangular, ciliate, with scarious margins. Corolla cream, pale sulphur to greenish yellow; standard 13.2–15.3 mm long, lamina 8.1–8.8 × 10–12.5 mm, obovate-trilobate, emarginate, with two gibbous in middle, claw 5.1–6.5 × 5.5–7 mm; wing 13.2–15 mm long, lamina 8–10 × 4.6–5.2 mm, 5–6 × 1.1–1.5 mm; keel 11–13 mm long, with a rostrate apex, lamina 6–8 × 3.5–5 mm, claw 5–6 × 1.2–1.5 mm. Stamens 10–12 mm, connate for 7–8 mm. Anthers 0.8–1.1 mm. Ovary glabrous; stylus spathulate at apex, 4–6 × 1.1–1.4 mm, bearded surface 3–4 mm. Legume linear-oblong, 45–60 × 7–9 mm, glabrous, reticulate, straw-colored. Ovules 8–12; seeds 3–5, subquadrangular, 3.5–5 × 3–4 mm, brownish, smooth, hilum ca. 2 mm long.

Distribution and habitat:—Specimens of Lathyrus turcicus were collected from W of Durhasan Village (Bursa, Türkiye). It is estimated that the variety grows in rocky slopes in degraded oak forest openings, approximately between 900 and 950 m a.s.l. There are many degraded forests and rocky slopes around Durhasan Village and Büyükorhan District. The probability that the taxon is also grown in this places is rather high, but there is still no data about this. Consequently, at present, the taxon is an endemic of Türkiye and when the area of distribution is considered, it is in the transition zone of Mediterranean and Euro-Siberian phytogeographic regions ( Figure 3 ).

Phenology:—Flowering time August‒September, fruiting time September‒October.

Etymology and Turkish name:—The species is named after the country of Türkiye. “ Türk burçağı” was suggested as the Turkish name for the new species.

Conservation status:—According to the existing data, Lathyrus turcicus is a species only known from the type locality. Approximately 100 individuals were counted in the type locality. The taxon grows forest clearings (oak) and rocky slopes in W of Durhasan Village. There are agricultural areas and an irrigation dam in the close surroundings of the individuals belonging to the taxon. On the other hand, there is a very low probability of these areas becoming completely agricultural lands in the future. When the areas where the taxon could be grown are considered, it is estimated that L. turcicus showed a distribution on an area smaller than 100 km 2. When the existing or envisaged threats are evaluated together, the taxon being known from only one address at present (area of life less than 10 km 2) and the breadth of the area of distribution calculated (less than 100 km 2), it was decided that it would be suitable to propose the Critically Endangered [CR B1ab(i)+CR B2b(ii)] classification for the extinction risk of the taxon ( IUCN Standards and Petitions Committee 2023).

Specimens examined:— Lathyrus pallescens : TÜRKİYE. Ardahan: Göle, plateau of Karlıyazı village, around Kartaltepe , 10 July 1981, N. Demirkuş 1066 ( HUB!); between Ardahan and Kartaltepe , along the road, 15 July 1981, N. Demirkuş 1131 HUB !); Kars: Yağmurlu Dağı , between Karaurgan and Sarıkamış, 2200 m a.s.l., 13 June 1957, P. H. Davis 29483 & I. C. Hedge ( E, E00370297 , virtual image!; ANK!); Yağmurlu Dağ, above Karaurgan , 2100 m a.s.l., 23 August 1957, P. H. Davis 32608 & I. C. Hedge ( E, E00370296 , virtual image!; ANK!); Kısır Dağı, 2200 m a.s.l., 30 June 1957, P. H. Davis 30447 & I. C. Hedge ( E, E00370294 , virtual image!; ANK!); between Kars and Susuz , 1800 m a.s.l., 15 June 1957, P. H. Davis 29579 & I. C. Hedge ( E, E00287613 , virtual image!; ANK!); Sarıkamış , 2100 m a.s.l., 07 July 1957, P. H. Davis 30798 & I. C. Hedge ( E, E00370295 , virtual image!; ANK!); Sarıkamış – Karakurt road, Keklikderesi place, pine clearings, 1800–1900 m a.s.l., 20 June 1979, O. Güneş 1257 ( HUB!); Kağızman, Denizgölü village , Mantardüzlüğü place, 2000 m a.s.l., 16 June 1980, O. Güneş 1663 ( HUB!) ; Ağrı: Kars road, N. of Ararat [Ağrı Mountain], 1900 m a.s.l., 23 June 1971, Brown 572 ( E, E00158118 , virtual image!) ; 2 km SW of Hamur (Murat valley), 1670 m a.s.l., 01 June 1976, Davis 44060 ( E, E00370300 , virtual image!) .

The first comprehensive information in Türkiye about the genus Lathyrus and section Platystylis was included in Volume 3 of the work titled “ Flora of Turkey and the East Aegean I slands”. The general characteristics of the species belonging to the sect. Platystylis are as follows; perennial, erect to ascending, stem angled; leaves pinnate to subdigitate, leaflets 1–7-paired, oblog to linear, parallel-veined from base, stipules semi-sagittate; inflorescences few or several-flowered; styles not or rarely twisted, linear to broadly spathulate; legumes not stipitate and gland dotted, seed rough or sooth and hilum relaively long ( Davis 1970, Rechinger 1979).

Lathyrus pallascens is one of the 15 species of the section known from Türkiye ( Davis 1970, 1988, Güneş & Sesal 2010). This species grows in N. Balkans, Hungary, Romania, C. & S. Russia, Crimea, Transcaucasia and N.E. Türkiye (especially in Kars Province) between 1800–2200 meters. The flowering period of the species is June-July and it prefers high mountain steppes, meadows and rocky slopes as habitat.

The moment the Lathyrus turcicus was seen for the first time, the most interesting aspect was that it was small flowers and large fruits. Lathyrus turcicus is similar to L. pallascens in terms of shape and size of leaves and seeds, and color of petals. However, in the L. turcicus specimens, there are stipules shorter than petiole, glabrous calyces, short petals and wider legumes ( Table 1 , Figs. 1 and 2 ).

Figures

FIGURE 1. Lathyrus turcicus. A: habit (holotype), B: flower, C: legume.

FIGURE 2. The flower parts of Lathyrus turcicus. A: calyx, B: standard, C: wings, D: keel, E: stamens and ovary, F: seed (scale bar: 3 mm).

FIGURE 3. Distribution map of Lathyrus turcicus (★) and L. pallascens (■).