Gladiolus hamzaoglui H. Duman, Sağıroğlu & Tekşen, 2021

Tekşen, Mehtap, Duman, Hayri & Sağiroğlu, Mehmet, 2021, A new Gladiolus (Iridaceae) species from East Anatolia (Turkey): Gladiolus hamzaoglui, Phytotaxa 496 (3), pp. 245-260 : 247-255

Gladiolus hamzaoglui H. Duman, Sağıroğlu & Tekşen sp. nov. ( Figures 1–5 , Table 1–2).

Type: — TURKEY. Erzincan: İliç, N of Çakmaktepe , 1290 m elevation, serpentine gravelly slopes and slightly moist meadows, 10 July 2020, H . Duman 10626 (holotype GAZI!; isotypes HUB!, ANK!) .

Diagnosis: — Gladiolus hamzaoglui is close to G. halophilus by corm, flower, fruit, and seed characteristics, and it is related to G. anatolicus by leaves, spathe valves, and flower features. It mainly differs from G. halophilus by having tunics papery, with parallel fibres (vs. coriaceus, reticulate fibrous), leaves green (vs. dull green), lower spathe valves width 6–12 mm (vs. 2–5 mm), spathe valves color green, membranous at margin (vs. dull green to greyish), flower tube distinctly curved (vs. slightly curved), upper perigone segments spathulate (vs. rhomboid-elliptic), upper lateral segment limb length 28–30 mm (vs. 20–25 mm), anthers yellow with purple stripe (vs. brownish-green), stigma branches length 5–6 mm (vs. 2–3 mm), seed shape elliptic to narrowly oblong (vs. obovate to oblong), and seed wings 0.3–0.7 mm wide (vs. 0.8–1.5 mm). It also differs from G. anatolicus because of having ovoid corm (vs. obovoid), tunics with parallel fibres (vs. reticulate fibres), leaves green (vs. dull green), spathe valves color green, membranous at margin (vs. dull green), spike secund (vs. not markedly secund, distichous), perigone rose-pink (vs. liliac-purple), flower tube distinctly curved (vs. slightly curved), upper perigone segments spathulate (vs. elliptic to elliptic-oblong), upper median segment limb length and width 30–35 × 13–15 mm (vs. 16–28 × 9–12 mm), upper lateral segment limb length 28–30 mm (vs. 12–24), lower median segment limb length 22–28 mm (vs. 12–21 mm), lower lateral segment limb width 9–11 mm (vs. 6–7 mm), anthers yellow with purple stripe (vs. brownish), stigma branches length 5–6 mm (vs. 1.0– 2.5 mm), capsule obovoid (vs. ellipsoid to oblong), seed shape elliptic to narrowly oblong (vs. ellipsoid-triquedrous), seed wings 0.3–0.7 mm wide (vs. unwinged).

Perennial, glabrous, generally in groups of a few plants or solitary. 1–3 piece contractile roots sometimes continue during the mature stage. Corm symmetrical, 20–30 × 12–15 mm, ovoid; tunics several layers, brownish, papery with parallel fibres. Stem 40–50(–70) cm long, erect; stem width 2–3(–6) mm diameter at gound level. Cataphylls apparently two, pale purple and firm membranous, upper cataphylls acute, middle truncate. Lower leaves emerge from or near the upper cataphyll. Leaves 4–5, 13– 45 cm × 3–7(–14) mm; linear to linear-lanceolate, acute to acuminate, the lower leaves equalling or exceeding the base of inflorescence, venation irregularly spaced parallel, not glaucous. Spathe valves unequal, green, membranous at margin, lanceolate, lower 20–30 × 6–12 mm, upper 10–15 × 1.5–2 mm. Inflorescence (5–)6–8(–10) flowered, lax, spike secund; flowers rose-pink; tube distinctly curved; posterior 10–12 mm long, anterior 10–15 mm long; upper segments spathulate with 5–10 mm long clawed, upper median segment limb (UMS) 30–35 × 15 mm, acute, upper lateral segment limb (ULS) 28–30 × 8–10 mm, acuminate; lower segments spathulate with 7–10 long clawed; lower median segment limb (LMS) 22–28 × 6–8 mm, acute; lower lateral segment limb (LLS) 20–25 × 9–11 mm, acuminate. Filaments (12–) 15–18 mm, adnate to perigone tube, filiform, yellowish; anthers shorter than filaments, 6–9(–10) mm long, yellow with purple stripe, basifixed, included. Ovary 3-locular, inferior. Style 30–35 mm long, filiform, rose-pink, included, stigma with 3 equal spathulate branches, branches 5–6 mm long. Fruits loculicidal capsule, obovoid, 12–15 × 6–12 mm, many seeded. Seeds 5.3–7 × 2–4 mm, elliptic to narrowly oblong, reddish-brown, wing 0.3–0.7 mm wide ( Figures 1–2 ).

Distribution, Habitat, and Ecology: — Gladiolus hamzaoglui grows on serpentine bedrock around the province of Erzincan (city center, İliç, Kemaliye) in slightly salty meadows and slightly moist gravelly-meadow slopes (Fig. 3). Therefore, the localities where the species spread are very fragmented, with small populations. It grows with Juncus inflexus L., Inula aucherana DC. , Epipactis veratrifolia Boiss. & Hohen , Dactylorhiza Neck. ex Nevski sp. pl. at an elevation of 1250–1500 m. Flowering period extends from late June to July, and fruiting period from August to September.

Conservation status: — The new species is known from four locations. Its extent of occurrence (EOO) is less than 10.000 km 2, and the area of occupancy (AOO) is less than 20 km 2 (criterion B1, B2); number of locations is less than five (a), and with an estimated continuing decline (b) of occupancy (ii), quality of habitat (iii), number of subpopulations (iv). Because of ongoing mining activities in İliç area, this new species is assessed to be considered as “Endangered: EN B2ab (ii, iii, iv)” ( IUCN 2019).

Etymology: — The species is named after dear Turkish botanist Prof. Dr. Ergin Hamzaoğlu (Gazi University, Ankara).

Additional specimens examined (paratypes): — TURKEY. Erzincan: Kemaliye, Salihli köyü çevresi, 1400– 1500 m elevation, serpentine gravelly slopes and moist meadows, 10 July 2020, H . Duman 10619 ( GAZI); İliç, N of Çakmaktepe , 1278 m elevation, serpentine gravelly slopes and slightly moist meadows, 10 September 2019, H . Duman 10658 ( GAZI) (fruit); Erzincan-Kelkit, 8th km, inside the valley, 1650 m elevation, 12 July 2012, E . Hamzaoğlu 7412 ( GAZI); ibidem, 27 July 2011, E . Hamzaoğlu 6228 ( GAZI); plain E . of Erzincan, 1250 m elevation, slightly saline marsh, 30 July 1957, Davis 31846 & Hedge ( E00337508 !, ANK!) .

Seed micromorphology: — Gladiolus hamzaoglui differs from G. halophilus in terms of 5.30–7.00 × 2.07–2.52 × 0.60–1.05 mm seed dimensions (L × W × T) (vs. 3.95–6.00 × 2.70–3.07 × 0.79–1.20 mm), L/W ratio 2.04 and shape elliptic (vs. 1.71, obovate-oblong), ornamentation colliculate on the seed body (vs. reticulate- cellulate), ornamentation colliculate on wing (vs. reticulate-foveolate), periclinal cell walls convex (vs. concave), 0.30–0.70 mm wing width (vs. 0.80–1.50 mm), 1.50–2.53 mm wing length between funiculus and seed (vs. 0.61–1.44 mm). Both species are akin to each other by their reddish-brown seed colour, rugose and well-developed cuticle type on the seed body, smooth epiculticular wax on wing, polygonal testa epidermal cells shape, uniformly thickened, and straight anticlinal cell walls ( Table 1, Fig. 4 A-4B).

FIGURE 3. Distribution map of Gladiolus hamzaoglui (▼), G. halophilus (█), G. anatolicus (█), and G. illyricus (●).

Gladiolus hamzaoglui also differs from G. anatolicus in terms of 5.30–7.00 × 2.07–2.52 × 0.60–1.05 mm seed dimensions (vs. 2.02–3.19 × 1.33–2.82 × 0.92–2.03 mm), L/W ratio 2.04 and shape elliptic (vs. 1.49, ellipsoidtriquedrous), reddish-brown seed color (vs. brown), ornamentation colliculate on the seed body (vs. rugose-reticulate), periclinal cell walls convex (vs. concave), seed winged (vs. unwinged), and their similar seed characteristics are rugose and well-developed cuticle type on the seed body, polygonal testa epidermal cells shape, uniformly thickened, and straight anticlinal cell walls ( Table 1, Fig. 4 A-4C).

Furthermore, G. hamzaoglui differs from G. illyricus by having 5.30–7.00 × 2.07–2.52 × 0.60–1.05 mm seed dimensions (vs. 3.33–4.85 × 2.26–3.44 × 0.64–0.91 mm), L/W ratio 2.04 and shape elliptic (vs. 1.57, obovate to oblong), reddish-brown seed colour (vs. brown), ornamentation colliculate on the seed body and wing (vs. reticulate), periclinal cell walls convex (vs. concave), 0.30–0.70 mm wing width (vs. 0.20–0.40 mm), and 1.50–2.53 mm wing length between funiculus and seed (vs. 0.15–0.40 mm). These two species share some characters such as the presence of wing, rugose and well-developed cuticle type on the seed body, smooth epiculticular wax on wing, polygonal testa epidermal cells shape, uniformly thickened, and straight anticlinal cell walls ( Erol et al. 2006).

Erol et al. (2006) and Zhygalova et al. (2014) concluded that the seed characteristics have great systematic significance and should be used in taxonomic studies. The most important diagnostic seed characteristics are seed shape, presence of wing, anticlinal and periclinal cell features, and ornamentation. In their SEM study, Erol et al. (2006) defined six Gladiolus species have four types of seed surface structure based on the anticlinal epidermal cell wall of the testa ornamentation, and determined two types of cuticular structure based on periclinal wall as furrowed and irregular wrinkles. Among these types, G. hamzaoglui has colliculate type ornamentation while G. halophilus has reticulate-cellulate, G. anatolicus has rugose-reticulate, and G. illyricus has reticulate type ( Erol et al. 2006). In the present study, G. hamzaoglui , G. halophilus , and G. illyricus were determined to possess rugose and well developed cuticle type on the seed body and no wax on the wings. According to Erol et al. (2006), G. halophilus has furrowed, G. anatolicus , and G. illyricus have irregular wrinkles type of cuticular structure based on periclinal wall. Barthlott (1981) stated that epidermal characteristics do not vary easily with habitat differences. The results in the present study are consistent with those by Erol et al. (2006), based on seed characteristics (only anticlinal and periclinal epidermal cell wall and SEM microphotographs) of six Gladiolus species , including G. halophilus , G. anatolicus , and G. illyricus . Consequently. we also conlude that seed characteristic are a significant and reliable criterion for distinction of Gladiolus species.

Pollen morphology: — Pollen grains of G. hamzaoglui are large, monosulcate, heteropolar, subprolate (LA/SA ratio 1.29), long axis (LA) 63.11–78.36 μm and short axis (SA) 47.21–67.54 μm; sulcus length 57.70–71.09 μm, sulcus width 33.44–55.14 μm, sulcus length/width ratio 1.34, sulcus membrane two banded operculate, operculum bands 6.72–15.24 μm wide, interoperculate distance 4.75–12.45 μm; exine 1.48–2.46 μm thick, intine 0.98–2.13 μm in thickness, thicker in aperture region, 2.13–4.10 μm thick; exine ornamentation microechinate, perforate; apex of sulcus round based on LM; sulcus margo irregular, sulcus almost extends the full length of the long axis of the grain based on SEM (Oymak Dönmez & Işık 2008) ( Table 1, Fig. 5A ).

As Gladiolus species usually spread in dry and arid habitats, they have a large sulcus and a thin exine to protect their large pollen grains, both against dehydration from aperture and against bacteria and mushroom pathogens. Gladiolus hamzaoglui possesses a two-banded operculum which is common to Iridaceae family. The operculum enables pollen grains to expand or shrink as a reflex to external conditions (Oymak Dönmez & Işık 2008). In Gladiolus , the intine has thickened in aperture, the exine has shrunk, and the exine spinules have developed for the same reason (Oymak Dönmez & Işık 2008). Walker (1974) states that a decrease in ectexine thickness is a significant development in pollen evolution for angiosperms. LM and SEM analyses data for G. hamzaoglui , G. halophilus , and G. anatolicus are given in Table 1.

Qualitative and quantitative values of pollen grains are very similar for G. hamzaoglui , G. halophilus , G. anatolicus , and G. illyricus , they all sharing microechinate, perforate exine ornamentation, tectate-columellate pollen wall type, two banded operculum, irregular sulcus margo, and pollen LA, SA, sulcus lenght and width, operculum width, exine and intine dimensions. However, G. hamzaoglui and G. halophilus have subprolate pollen graoins whereas G. anatolicus has prolate grains, and G. illyricus oblate grains (Oymak Dönmez & Işık 2008, Halbritter & Auer 2021). There are high standard deviation values for pollen LA, SA, sulcus width and length, and interoperculate distance. It means that the values are variable in a larger range for G. hamzaoglui , G. halophilus , and G. anatolicus . The variability is high for G. halophilus , but low for G. illyricus (for LA and SA) as reported by Oymak Dönmez & Işık (2008). The pollen characteristics of G. halophilus and G. anatolicus on LM (LA, SA, pollen wall type, and sulcus membrane) are coherent with Oymak Dönmez & Işık (2008). In the present study, more detailed pollen characteristics and microphotographs (LM and SEM) were analysed and given for three species.

As shown by Aktürk et al. (2006) and Oymak Dönmez & Işık (2008), pollen structure, which is a taxonomically important characteristic used at genus level in Iridaceae , cannot provide sufficient distinction for the generic subcategories of Gladiolus and the species compared in the present study. However, pollen shape and dimensions are determinative and useful for pollen micromorphological analysis for Gladiolus species.

Taxonomic relationships: — In their notes in Gladiolus halophilus, Tan & Edmondson (1984) mentioned it as located at “B7: Erzincan: E of Erzincan, 1250 m, D. 31846!” and as a specimen with characters intermediate between G. halophilus and G. illyricus . The specimen that was mentioned in Tan & Edmondson (1984) was found at “E and ANK” herbaria. The species described in the present study as G. hamzaoglui , sampled from İliç and Kemaliye, is consistent with the one cited by Tan & Edmondson (1984), based on its with its morphology and provenance. Hamilton, however, noted on the sample tag as “probably a new taxon” on 20 April 1982. Moreover, there are some newly discovered and published species from the vicinity of Erzincan, Ilic, which are interesting in terms of floristics and biogeography, i.e. Allium shahinii H. Duman & Ekşi ( Ekşi & Duman 2020), Silene dumanii Kandemir, G.E. Genç & İ. Genç ( Kandemir et al. 2009), Tanacetum erzincanense Korkmaz, Kandemir & İlhan ( Korkmaz et al. 2015), and Aethionema erzincanum Kandemir & Aytaç ( Kandemir et al. 2017).

Based on the primary morphological analyses on the specimen collected during the field studies in Erzincan, İliç, and Kemaliye, which have the potential of a new species related to G. halophilus and G. illyricus , we determined that those specimen are akin to G. anatolicus according to their leaves, spathe valves, and flowers features, and to G. halophilus by their winged seed characteristics, and to G. illyricus by some leaf and flower characteristics, and winged seed. Most probably, it was assumed as an intermediate species by Tan & Edmondson (1984) since the seeds of G. illyricus are winged as well.

The root has 1-3 thickened contractile roots when the plant is immature ( Fig. 1D ). They disappear when it matures. No cormel formation is seen on this contractile root structure expect for lateral roots. In the maturing process of the plants, cormels are formed next to the main corm. Cormels may also be seen at the tip of stolons of Gladiolus halophilus . It is common to Gladiolus as well. Assuming it may be a different and new species, we collected specimen at various stages and determined this feature. It may explain why this species spreads in clusters in its habitat.

According to Erol et al. (2006) and Karaismailoğlu (2015, 2018), seed characteristic are not sufficiently used in Iridaceae though they possess great systematic significance. In the present study we found that seed characteristics can be satisfactorily used in taxonomic distinction of Gladiolus taxa. In Turkey, winged seeds are observed in five Gladiolus species , i.e. G. halophilus , G. attilae , G. illyricus , G. aladagensis , and G. hamzaoglui .

In the present study, the newly described species was compared morphologically with G. halophilus as its closest species, and also with G. anatolicus and G. illyricus due to leaf and flower similarities ( Table 2). Gladiolus hamzaoglui also differs from G. attilae by the secund inflorescence, distinctly curved flower tube, flower colour, anther colour, and seed wing width.

Gladiolus hamzaoglui is closely related to G. halophilus by their corm shape, secund inflorescence, filament and anther length, obovoid fruit, and winged seed characters, and it is related to G. anatolicus by leaf dimensions, spathe valves length, lower perigone segments shape, claw and limb length, filament and anther length, and stigma branches length. In addition, G. hamzaoglui is also related to G. illyricus with leaf colour and dimensions, and secund inflorescence, number of flower, UML and ULS limb dimensions, LMS and LLS limb length, filament and anther length, and winged seed. The comparison of morphological characters among G. hamzaoglui , G. halophilus , G. anatolicus , and G. illyricus is given in Table 2. G . hamzaoglui can be easily distinguished from G. halophilus by having 1–3 thickened contractile roots in the immature stage, usually absent in mature (vs. contractile roots absent at all stage), tunics papery, with parallel fibres (vs. coriaceus, reticulate fibrous), leaves width 3–7 (–14) mm and green (vs. 1–3 mm and dull green), lower spathe valves width 6–12 mm (vs. 2–5 mm), upper spathe valves width 1.5–2 mm (vs. 2–5 mm), spathe valves color green, membranous at margin (vs. dull green to greyish), (5–)6-8(–10) flowered (vs. 2–5), perigone rose-pink (vs. pink to magenta-pink), flower tube distinctly curved (vs. slightly curved), upper perigone segments spathulate (vs. rhomboid-elliptic), ums limb length and width 30–35 × 13–15 mm (vs. 20–30 × 10–13), ULS limb length 28–30 mm (vs. 20–25), lower perigone segments claw length 7–10 mm (vs. 4–8), LMS limb length 22–28 mm (vs. 15–25), LLS limb length 20–25 mm (vs. 24–28 mm), anthers yellow with purple stripe (vs. brownish-green), filament length (12–) 15–18 mm (vs. 10–15 mm), stigma branches length 5–6 mm (vs. 2–3 mm), seed shape elliptic to narrowly oblong (vs. obovate to oblong), seed wings 0.3–0.7 mm wide (vs. 0.8–1.5 mm). It differs from G. anatolicus by having 1–3 thickened contractile roots in the immature stage, usually absent in mature, ovoid corm, with parallel fibres tunics, 40–50(–70) cm long stem, 3.0–7.0(–14) wide leaves, green leaves, 6–12 mm wide lower spathe valves, 1.5–2 mm upper spathe valves width, green and membranous at margin spathe valves, secund spike, (5–)6-8(–10) flowered inflorescence, rose-pink perigone, distinctly curved flower tube, spathulate upper perigone segments, 5–10 mm long upper perigone segments claw, 30–35 × 13–15 mm ums limb length and width, 28–30 mm long ULS limb, 7–10 mm long lower perigone segments claw, 22–28 mm long LMS limb, 9–11 mm wide LLS limb, yellow with purple stripe anthers, 5–6 mm long stigma branches, obovoid capsule, elliptic to narrowly oblong seed shape, and winged seed (in G. anatolicus : contractile roots absent at all stage, corm obovoid, tunics with reticulate fibres, stem length 18–40 cm, leaves width 2–4 mm, dull green leaves, lower spathe valves width 4–7 mm, upper spathe valves width 2–4 mm, spathe valves color dull green, spike not markedly secund, distichous, inflorescence 3–4(–5) flowered, perigone liliac-purple, flower tube slightly curved, upper perigone segments elliptic to elliptic-oblong, upper perigone segments claw length 0–5 mm, ums limb length and width 16–28 × 9–12 mm, ULS limb length 12–24 mm, lower perigone segments claw length 8–15 mm, LMS limb length 12–21 mm, LLS limb width 6–7 mm, anthers brownish, stigma branches length 1–2.5 mm, capsule ellipsoid to oblong, seed shape ellipsoid-triquedrous, and seed unwinged). The new species also differs from G. illyricus because of having 1–3 thickened contractile roots in the immature stage, usually absent in mature (vs. contractile roots absent at all stage), tunics papery, with parallel fibres (vs. membranous, with parallel fine fibres), stem 40–50(–70) long (vs. 25–70), lower spathe valves width 6–12 mm (vs. 3–6 mm), upper spathe valves width 1.5–2.0 mm (vs. 2–3 mm), spathe valves color green, membranous at margin (vs. dull green), flower tube distinctly curved (vs. slightly curved), upper and lower perigone segments spathulate (vs. rhomboid, elliptic or obovate to oblanceolate), upper perigone segments claw length 5–10 mm (vs. 0–3 mm), LMS limb width 6–8 mm (vs. 8–12 mm), anthers yellow with purple stripe (vs. brownish), filament length (12–) 15–18 mm (vs. 13- 14 mm), stigma branches length 5–6 mm (vs. 3–4 mm), capsule shape obovoid (vs. ellipsoid to obovoid) seed shape elliptic to narrowly oblong (vs. ovate to oblong), seed wings 0.3–0.7 mm wide (vs. 0.2–0.4 mm) ( Table 2).

Gladiolus hamzaoglui is distributed in East Anatolia on serpentine bedrock in slightly salty meadows and slightly moist gravelly-meadow slopes at an elevation of 1250–1500 m, whereas G. halophilus is distributed in Central Anatolia on salty meadows and steppes at an elevation of 900–1200 m. In Turkey, G. anatolicus is distributed in the Mediterranean Region on especially limestone rocky, alpine, steppe, forest and scrub areas between 0–2000 m elevation. Similarly, G. illyricus is also distributed in the Mediterranean Region on especially rocky limestone slopes, Pinus nigra forest, phrygana, near rivers at 0–1500 m elevation in Turkey ( Tan & Edmondson 1984) (Fig. 3). Gladiolus hamzaoglui and G. halophilus are Irano-Turanian, whereas G. anatolicus and G. illyricus are Mediterranean phytogeographical elements.

Figures

FIGURE 1. Gladiolus hamzaoglui (HD 10626). a, b) habitat; c) habitus; d) contactile roots at immature; e) inflorescence; f) capsules (photographed by H. Duman).

FIGURE 2. Gladiolus hamzaoglui. A1–A2) habitus; B) root type at immature individuals; C) perigone; D) stamen; E) style and stigma; F) capsule; G) seed (illustrated by F. Şen; Collection no: H. Duman 10626).

FIGURE 4. A) LM and SEM microphotographs of the seeds of Gladiolus hamzaoglui (HD 10658); B) G. halophilus (MT 3500); C) G. anatolicus (AAD 13070). Scale bar (sb) (a, d, g: General view in LM (sb: 2 mm); b, e, h, i: testa epidermal cells (sb: 50 μm); c, f: epidermal cells at the wing on SEM (sb: 100 μm).

FIGURE 5. Pollen grains LM and SEM microphotographs. A) Gladiolus hamzaoglui (HD 10626); B) G. halophilus (MT 3500); C) G. anatolicus (AG 8763). a, c: LM (a. Equitorial view; b. Proximal polar view; c. Distal polar view (two-banded operculum). Scale bar (sb): 20 µm). d, f: SEM (d. Equitorial view (sb: 10 µm). e. distal polar view (sb: 10 µm). f. exine surface (sb: 1 µm).