Gagea vanensis Tekşen, 2015

Tekşen, Mehtap & Erkul, Seher Karaman, 2015, Gagea vanensis, a new species and G. chomutovae, a new record from Southeastern Anatolia, Turkey (Liliaceae), Phytotaxa 188 (5), pp. 251-260 : 252-256

Gagea vanensis Tekşen & Karaman sp. nov. ( Figs. 1 –6).

Type: — TURKEY. Van: Gürpınar, Işıkpınar to Hacıköy , around the pond, N 38º18´,872, E 43º37´,032, 2154 m, steppe, 13 May 2010, M. Tekşen 2460 & S . Karaman (holotype GAZI!; isotypes ANK!, HUB!) .

Plants 5–15 cm tall, solitary. Roots thin, not enveloping the bulb, thickened roots absent. Bulb 4–10 × 4–9 mm, ovoid to globose, bulbils present from juvenile to mature ontogeny, united on the one side of bulb from the base, numerous, enclosed in common tunics, current year’s white to light-brown, 1–4 × 1–2.5 mm, ovoid-pyriform, last year’s black, pyriform, reticulate, on the base of the bulbs, 1–4 × 1.5–2.5 mm; tunics coriaceous, black; neck 5–13 mm long, splitting at the top. Peduncle erect, sometimes arch-shaped, glabrous. Basal leaf 1, 60–150 × 0.5–1.5 mm, linear, cylindrical, ± circular in cross section, solid, equalling or rarely slightly exceeding the inflorescence, glabrous. Cauline leaves alternate, the lowest one 15–65 × 2–3 mm, linear-lanceolate, enveloping the stem at the base, equalling or shorter than the inflorescence, rarely slightly long, glabrous or margins sparsely ciliate; other cauline leaves shorter, 5–30 × 1.5–2 mm, not exceeding the inflorescence, linear to linear-lanceolate, acute, ciliate at the margin. Inflorescence cymose, 2–16 flowered; pedicels unequal, nodding in bud, glabrous, longest pedicels 15–30 mm, as long as the flowers or to 2.5 times longer. Outer tepals 6–10 × 2–2.5 mm, oblanceolate, elliptic, obtuse, inner tepals 8–12 × 2.5–3.5 mm, spathulate, obtuse; abaxially green with 3 veins, adaxially yellow, reddish at tips, glabrous. Stamens 7–8 mm, filaments 6–7 mm, anthers spherical, 0.5–1 × 0.5–1 mm, yellow. Ovary 3–4 × 1–2 mm, obovoid, style 3–4.5 mm, stigma capitate. Capsule and seeds not seen.

Etymology: — The specific epithet is derived from the locality of the type specimen, Van Province.

Additional specimens examined (paratypes): — TURKEY. Van. Gürpınar, Güzelsu to Uçgen village , 3 km from Hoşap , 2056 m, steppe, 11 May 2010, M. Tekşen 2413 & S . Karaman (GAZI!); Gürpınar, Güzelsu, Hoşap to Van, 8 km from Hoşap , 1960 m, steppe, 14 May 2010, M. Tekşen 2483 & S . Karaman (GAZI!); ibidem, 18 May 2013, M. Tekşen 2909 & S . Karaman (GAZI!); Gürpınar , Van to Başkale, 12 km to Hoşap, around of Zernek Dam , 1979 m, steppe, 10 May 2010, M. Tekşen 2392 & S . Karaman (GAZI!).

Distribution, Habitat and Ecology: — Gagea vanensis is a putative Turkish endemic species and is only known from four populations in Van Province, South Eastern Anatolia ( Fig. 1 ). It grows on roadsides and steppe at 1960–2056 m altitude with Astragalus L. sp. pl., Gladiolus atroviolaceus Boiss. , Muscari armeniacum Leichtlin ex Baker , Fritillaria crassifolia Boiss. & Huet subsp. kurdica (Boiss & Noë) Rix , Iris reticulata M.Bieb. var. reticulata , Iris sari Schott ex Baker , Allium scabriscapum Boiss. & Kotschy , Gagea confusa A.Terracc., G. bulbifera (Pall.) Salisb. , G. reticulata (Pall.) Schult. & Schult. f., Ceratocephala falcata (L.) Pers. Flowering time is late April and May.

of a mature peduncle (Scale bar: 10 mm).

Suggested conservation status: — Gagea vanensis is found between Güzelsu and Gürpınar, Van. It is an Irano- Turanian floristic region element. G. vanensis can be found as small, separate, and few-numbered populations (less than 100 mature plants) in the areas. Its populations are under road widening works and frequently grazing effects. The new species should be regarded as endangered VU B2ab(i, ii, iv): area of occupancy less than 2000 km 2, known at no more than 10 locations; inferred decline in the area based on IUCN threat categories ( IUCN 2013).

Anatomy:—Transverse sections of basal leaves in Gagea vanensis are circular in outline with 5 circularly-arranged bundles. Basal leaves in juvenile plants have two united vascular bundles. One layer hypoderm is present beneath the epiderm. The mesophyll includes both spongy and palisade parenchyma. Stomata are 25–26 × 17–20 µm ( Fig. 5 ). The outline of the transverse section of peduncle is circular. The region cortex is filled with three to four layers of parenchyma cells without collenchyma. Each vascular bundle is surrounded by a parenchymatous vascular sheath. Sclerenchyma is five to six layers thick and covers over the phloem, and it forms a continuous annulus. The xylem is covered with the pith. The center of peduncle becomes slightly fistulose ( Fig. 5 ).

Pollen morphology:—The pollen grains are heteropolar, and the aperture is monosulcate type. The pollen shape is oblate with an elliptic equatorial outline, polar axis 38–48 μm, equatorial axis 50–60 μm. The ornamentation is reticulate-cristate. The sulcus is operculate, and the operculum membrane shows rugulate ornamentation. The sulcus has an elliptical shape, 44–50 µm length and 22–26 µm width. The exine semitectate, 1.5–2.3 μm thick, the intin is 0.7–1.2 μm thick (Fig. 6).

Taxonomic relationships:— G. vanensis is close to G. ova species group. The main differences rely on the features of vegetative bulbils (number, arrangement, shape, sculpture, and color in mature age) and the color of tepals. In the description of G. ova, Stapf (1885) specifies that the color of tepals is faintly yellow, the external tepals are narrowly elliptic-elongated, and the internal tepals are narrowly obovate-elongated. However, up to 5–6 taxa from this group are present in the Irano-Turanian region. These are G. stipitata , G. absurda , G. kunawurensis , G. × turanica ( Levichev 1990: 663), and G. rubinae ( Ali 2006: 45) . Some of them have perigone changing from milky white to yellow ( G. ova : only at the first year milky white, then straw-coloured) ( Levichev 1990, 2006), others with always yellow perigone ( G. absurda ). Ali (2006) described G. rubinae as closely related to G. stipitata and G. × turanica. G. rubinae differs from G. stipitata and G. × turanica in large cellular sculpture of bulbils and differs from G. ova in having yellow (instead of milky-white and faintly yellowish) tepals and with an attachment of vegetative bulbils in the form of a wide lacuna (instead of attachment in the form of narrow strip) ( Ali 2006). This species is known only from Baluchistan in Pakistan ( Ali 2006, Ali & Levichev 2007).

xylem; P, parenchyma; PH, phloem; PI, pith; AS, air space; ST, stoma; CR, cortex).

G. vanensis differs from G. chomutovae in the absence of sclerified roots and the cross section of the basal leaf solid with five vascular bundles (in G. chomutovae sclerified roots present and cross section of the basal leaf hollow, with more than ten vascular bundles; Pascher 1907, Grossheim 1935, Zarrei et al. 2007, 2011 a, Peterson et al. 2008). G. vanensis differs from G. ova in the absence of sclerified roots, 5–13 mm neck, 2–16 flowered inflorescence (more flowers occur during the later stages of the ontogeny), tepals abaxially green, adaxially yellow, reddish at tips, outer tepals oblanceolate to elliptic, inner tepals spathulate (in G. ova sclerified roots present in juvenile specimens, and absent in generative period, neck absent, inflorescence 3–9 flowered, tepals abaxially and adaxially faintly yellow, not reddish at tips; outer tepals narrowly elliptic-oblong, inner tepals narrowly obovate-oblong; Grossheim 1935, Ali & Levichev 2007, Zarrei et al. 2011b, Peterson et al. 2011). G. vanensis differs from G. stipitata in the absence of sclerified roots, bulbils numerous during whole ontogeny, basal leaf equalling or exceeding inflorescence, peduncle 2–4 cm; tepals abaxially green, adaxially yellow, reddish at tips, outer tepals 6–10 × 2–2.5 mm, inner tepals 8–12 × 2.5–3.5 mm (in G. stipitata sclerified roots present, juvenile plants with a loose groups of bulbils, adult ones with a single bulbil; basal leaf shorter to inflorescence, peduncle 6–10 cm, tepals abaxially green, adaxially brilliant yellow not reddish at tips, outer tepals 10–13 × 3–3.5 mm, inner tepals 12–14 × 4–5.5 mm; Grossheim 1935, Zarrei et al. 2007, Peterson et al. 2011). G. vanensis differs from G. absurda in its 4–10 mm × 4–9 mm bulb, bulbils numerous during the whole ontogeny; basal leaf solid; inflorescence 2–16 flowered; outer tepals oblanceolate to elliptic, inner tepals spathulate (in G. absurda bulb 10–14 mm; bulbil in small group during the whole ontogeny, basal leaf fistulose, inflorescence (1–)3–4 flowered, outer tepals rhombic, inner tepals narrowly obovate-oblong; Levichev 1990, Ali & Levichev 2007). G. vanensis differs from G. kunawurensis in its cauline leaves equal or shorter than the inflorescence, inflorescence 2–16 flowered; tepals abaxially green, adaxially yellow, always reddish at tips (in G. kunawurensis cauline leaves exceeding the inflorescence, inflorescence 3–5 flowered; tepals abaxially dull-greenish, adaxially white, not reddish at tips; Ali & Levichev 2007, Zarrei et al. 2011b; Peterson et al. 2011).

Figures

FIGURE 1. Distribution map of G. vanensis (●) and G. chomutovae (■) in Turkey.

FIGURE 5. A–D. LM and E–F. SEM micrographs of pollen grains in G. vanensis. (E. Pollen grain in distal polar view. F. Proximal face of pollen grain with reticulate-cristate tectum).