Festuca greuteri Martínez-Sagarra & Devesa, 2019

Martínez-Sagarra, Gloria & Devesa, Juan A., 2019, Two new taxa of Festuca (Poaceae) from the southeastern Iberian Peninsula, Phytotaxa 395 (4), pp. 251-264 : 253-256

Festuca greuteri Martínez-Sagarra & Devesa sp. nov. ( Figs. 2 − 3 )

Type: — SPAIN. Granada : Sierra de Guillimona, puerto de la Losa, 38º0’13”N 2º35’24”W, 1780 m elevation, 4 June 2014, calizas, en márgenes de carretera, E. López & G. Martínez-Sagarra, GM22/14 (holotype: COFC 65825!, Fig. 2 ; isotypes: COFC!) .

Description: —Perennial herb, tufted, culm up to 55(65) cm × 0.4–0.7 mm, erect, cylindrical, finely striated, glabrous, smooth or more rarely sparsely antrorse-scabrid under the inflorescence, with (0–)1(–2) visible nodes towards the lower part, covered at the base by imbricate leaf sheaths. Leaf sheath of non-flowering shoots with margins free for about 2/3–3/4 of their length, greenish-glaucous and herbaceous at the beginning, papyraceous and straw-coloured at maturity, pruinose or not, glabrous, smooth; auricles 0.1–0.5(–0.8) mm, sometimes unequal, obtuse, briefly ciliolate at the apex; ligule 0.1–0.5 mm, membranous, truncate, briefly ciliolate; leaf blade (1.5–)2–15(–20) cm × 0.6–1 mm, setaceous, rarely almost junciform, erect-curved, sometimes ± sigmoid at the end, ± rigid, not pungent, conduplicate, from elliptical to obovate (rarely V-shaped) outline in cross-section, continuous abaxial subepidermal sclerenchyma, sometimes somewhat interrupted, absent on the ribs, 7(–9) vascular bundles, 4(–6) grooves, and 3(–5) ribs in cross-section ( Fig. 4 ), green or usually greenish-glaucous, glabrous, smooth or antrorse-scabridulous, apex from obtuse to acute. Cauline leaves 1(–2), similar to those of non-flowering shoots, with auricles 0.2–0.8 mm, ligule 0.2–0.4 mm, and blade 1.3–6 cm × 0.4–0.7 mm. Panicle 2–8.5(–9) cm, dense, oblong-ellipsoidal, with 13–29(–32) spikelets and an axis provided with 9–11 nodes − the lowermost internode (0.5–)1.5–2.5(–3) cm −, antrorse-scabrid, with 1–3(–5) branches − first simple branch, 1–4 cm and with 2–6 spikelets −, solitary, erect, ± appressed, usually erect-patent at anthesis. Spikelets (5.5)6–9.5(–11.5) mm, laterally compressed, elliptic, green, greenish-glaucous or greenish-purple, with a pedicel of 0.5–4.5 mm, slightly thickened at the apex, (3–)4–7(–8) fertile florets and 1 apical and ± rudimentary sterile floret. Two glumes, unequal, narrowly scarious on margins, smooth or with scattered aculei at the edges of the upper half, acute or acuminate, the lower (1.6–)2–4(–4.3) mm, linear-lanceolate, with 1 nerve; the upper (3–)3.2–5(– 6.3) mm, ovate-lanceolate, with 3 nerves. Lemma (3.6–) 4.2–6.7 mm, ovate-lanceolate, acute, awned, with narrowly scarious margins, with sparse aculei in the upper half, greenish or greenish-purple at the margins and towards the apex, with 5 nerves, that of the basal floret with an awn of 0.1–1.4 mm, that of the second basal floret with an awn of (0.1–)0.2–2.3(–2.5) mm, and awns up to 2.5(–3) mm in the rest. Palea (3.5–)4–5.7(–6) mm, subequal or somewhat shorter than lemma, bidentate, with 2 scabrid keels. Anthers (1.7–)1.9–3.4(–3.6) mm, linear, yellow. Ovary glabrous. Lodicules 0.8–0.9 mm, bilobed. Caryopsis 2.6–3.4 mm, adhering to palea.

Eponymy: —The specific epithet honours Prof. emer. Dr. Werner Greuter (Università degli Studi di Palermo).

Phenology: —Flowering time, May to July; fruiting time, July to August.

Distribution and ecology: —Endemic to the southeast of the Iberian Peninsula ( Spain). The species is restricted to Baetic summit areas (Almería, Granada, Jaén, and Málaga provinces). It grows on open grasslands, scree of mountain meadows, and open scrubland, on basic substrates (limestones, dolomites, and marble dolomites); 1300–2200 m elevation ( Fig. 1 ).

Taxonomic remarks: — Festuca greuteri shows some variability in the size of the floral parts (the lowest values of spikelets and lemmas were observed in some specimens from Sierra de Baza and Sierra de Tejeda), and in the diameter, stiffness and anatomical pattern (in cross-section) of the leaf blade. Usually, plants of the easternmost populations show rigid leaf blades, elliptical and with a continuous ring of sclerenchyma in cross-section (e.g., in Sierra de María, Sierra de Guillimona, and Sierra de Castril). The diameter of the leaf blades is particularly small in individuals from Sierra de Mágina (leaf blades in cross-sections not shown), but it is quite variable depending on the plant habitat (see the variation of the leaf cross-sections among populations in Fig. 4 ). Plants of the western populations usually have more flaccid leaf blades, with a broken ring of sclerenchyma ‒ sometimes on very decurrent strands ‒ in cross-section (e.g., in Sierra de Camarolos, Fig. 4G ‒ J , although this character combination also appears in some individuals from other mountains when the soils are humid), and obovate or V-shaped outline ( Fig. 4 ). We observed that members of this species are usually glaucous and somewhat pruinose, but it is also a variable character (e.g., plants glaucous-pruinose are frequently found in Sierra de Guillimona, Sierra de Baza and Sierra de Tejeda).

The awn length, however, provides two variation patterns that are recognised here to define two subspecies. Plants with the second basal lemma bearing a short awn, up to 1.3(–1.5) mm, are included in subsp. greuteri , and are distributed throughout the area of the species; on the contrary, plants with long-awned lemmas (usually more than 1.5 mm in that of the second floret) are grouped in subsp. camarolensis , and are restricted to the Sierra de Camarolos and Sierra del Jobo (Málaga province), where it coexists (growing in the same area) with plants of the typical subspecies. Members of subsp. camarolensis can have slightly larger floral parts (glumes and lemmas), although overlapping those of subsp. greuteri .

Figures

FIGURE 1. A) Distributionmap of Festucagreuteri subsp.greuteri, F.greuteri subsp.camarolensis, F.longiauriculata andF.segimonensis. Main populations studied: 1, Sierra de Guillimona (type population of F. greuteri) and Sierra de la Sagra; 2, Sierra de Alcaraz; 3, Sierra de Cazorla and Sierra de Castril; 4, Sierra de María; 5, Sierra de los Filabres; 6, Sierra de Baza; 7, Sierra Nevada; 8, Sierra de Gádor; 9, Sierra de Mágina; 10, Sierra de Tejeda; 11, Sierra de Camarolos and Sierra de El Jobo. B) Habitat of F. greuteri subsp. greuteri (puerto de la Losa, Sierra de Guillimona).

FIGURE 2. Holotype of Festuca greuteri (Granada, Sierra de Guillimona, puerto de la Losa, COFC 65825).

FIGURE 3. Festuca greuteri subsp. greuteri (A–C and E–L) and F. greuteri subsp. camarolensis (D). A) Habit; B) Detail of the apex of the sheath and ligule in adaxial view; C−D) Spikelet; E) Lower glume in abaxial view; F) Upper glume in abaxial view; G) Lemma in abaxial view; H) Palea in abaxial view; I) Lodicule; J) Sexual whorls; K) Caryopsis in adaxial view; L) Caryopsis in abaxial view. Vouchers: Spain, Puerto de la Losa, Sierra de Guillimona, Granada, 4 June 2014, E. López & G. Martínez, COFC 61365 (F. greuteri subsp. greuteri); and Spain, Sierra de Camarolos, Málaga, 10 June 2015, B. Cabezudo, J. A. Devesa, G. Martínez & F. Soriguer, COFC 62140 (F. greuteri subsp. camarolensis).

FIGURE 4. Leaf blades in cross-section of Festuca greuteri subsp. greuteri (A–F), and F.greuteri subsp.camarolensis (G–K).Provenance of the material: Sierra de la Sagra (A, F), Sierra de Baza (B), Sierra de Tejeda (E), Sierra de Guillimona (D), and Sierra de Camarolos (C, G–K).