Limonium tobarrense J.Moreno, Terrones, M.

Moreno, Joaquín, Terrones, Alejandro, Alonso, María Ángeles, Juan, Ana & Crespo, Manuel B., 2016, Limonium tobarrense (Plumbaginaceae), a new species from the southeastern Iberian Peninsula, Phytotaxa 257 (1), pp. 61-70 : 65-67

Limonium tobarrense J.Moreno, Terrones, M. A.Alonso, Juan & M.B.Crespo sp. nov. ( Fig. 2 ).

Type:— SPAIN. Albacete: Tobarra, Saladar de Cordovilla, 30SXH 2066, 514 m a.s.l., 19 July 2014, Terrones & Moreno s.n. (holotype ABH-71924!, isotypes ABH-71925!, ABH-71926!, MA!).

Diagnosis:— Planta perennis notabilis subgeneris Limonii ad L. girardianum primu adspectu similis sed ea facile distinguitur caulium et apicis bractearum superioris densa pilositate. Folia spathulata , oblanceolata, mucronata. Spiculae dense dispositae (7–10 pro cm), 4–6 mm longae; bractea inferiore 1.0–1.5 × 0.5–0.75 mm longa; bractea media 1.3–1.5 × 0.3–0.5 mm longa; bractea superiore 3.5 × 3.0– 3.5 mm longa. Calyx 3.5 mm, ex bractea superiore c. 0.5–0.75 mm exsertus, post anthesin profunde laceratus; tubo calycis unilateraliter piloso. Petala violacea 5.5–6.5 × 1.5–2.0 mm. Combinatio pollinico-stigmatica e typo B (stigmatibus e typo “papillate” et pollinis granis reticulo perangusto e typo B).

Description:—Perennial plant, multicaule, with indumentum of short hairs, ± dense. Stump 3–12 cm. Leaves of the basal rosette oblanceolate to narrowly oblanceolate-spatulate [27–74(–80) × (5.0–)5.5–12.0(–15.0) mm], green at anthesis, smooth or verruculose on the upper surface, 1–3-nerved, scarious margin 0.1 mm wide, apiculate to blunt at the apex, shortly mucronate; petiole (1.0–)1.5–3.0 mm wide, as long as to 2/3 the length of the blade. Scapes 20–60 cm, erect, zigzag, densely hairy at least in the lower 1/3 part, densely hairy to hairless in the middle part, with hairs simple or gathered in groups of three; branching generally from the middle. Inflorescence with rhomboid to lanceolate outline (usually type C or E); sterile branches absent or with only some primary sterile branches. Primary branches up to 20 cm long, scarce and laxly disposed, almost straight, erect-patent to patent (branching angle 50°–65°), branched in the upper third. Terminal spikes 5–13(–16) mm, dense at the apex of the branches, straight; lateral spikes shorter than terminal spikes, 3.5–9.5(–11.5) mm. Terminal spikelets 4–6 mm long, densely arranged, (6–)7–10(–11) per cm, in bilateral disposition, each spikelet 2-flowered. Lateral spikelets 4.0– 5.5 mm, 2-flowered, densely arranged (4–9 per cm), in bilateral disposition. Outer bract 1.0–1.5(–2.0) × 0.5–0.75 mm, triangular-ovate, with subobtuse to blunt apex; hyaline margin broadly membranous; papillate-wrinkled and somewhat fleshy in the middle part, narrowly oblong tip not reaching the margin; hairy in the nerve. Middle bract 1.3–1.5 × 0.3–0.5 mm, oblong-elliptical to oblong-obovate, membranaceous, scarcely hairy. Inner bract (3.0–)3.5(–4.0) × 3.0– 3.5 mm, oblong-obovate, with hyaline-membranaceous margin; middle part 2.7–3.0 × 1.2–1.3 mm, somewhat fleshy with papillate-wrinkled upper middle, hairy at the apex ca. 0.1 mm, narrowly acuminate. Corolla 4.5–6.0 mm in diameter. Calyx (3.0–) 3.5 mm long, exceeding inner bract ca. 0.5–0.75 mm; tube densely hairy, with long hairs up to 0.3–0.4 mm; teeth 0.5–1.0 × 0.5 mm, broadly semielliptic and scarcely hairy; tube ribs ending above the middle of the tooth base; intercostal area densely hairy on one side, glabrescent to short hairy in the rest, the limb lacerated after anthesis. Petals 5.5–6.5 × 1.5–2.0 mm, cuneate, violet-bluish. Stigma filiform, covered with conical, subacute papillae (type “papillate”). Pollen grains very narrowly reticulate (type “B”). Pollen-stigma combination “ type B” (self-incompatible).

Ecology:— Limonium tobarrense grows on salt-silts and limestone clay soils (Tertiary and Quaternary substrates). These saline sites are placed at slightly higher elevations than the surrounding areas that can be flooded during winter.

Phytosociology:—The new species occurs in halophilous plant communities belonging to the class Salicornietea fruticosae, Ord. Limonietalia Br.-Bl. & O.Bolòs 1958, All. Lygeo sparti-Limonion angustebracteati, and grows together with e.g. Arthrocnemum macrostachyum ( Moricand 1820: 2) Moris in Moris & Delponte (1854: 35), Limonium cossonianum , Limonium delicatulum , Sarcocornia fruticosa ( Linnaeus 1753: 3) Scott (1977: 367) and Juncus maritimus Lamarck (1789: 264) .

Bioclimatology:— Limonium tobarrense is found in the low horizon of the Mesomediterranean Thermotype and semiarid Ombrotype (sensu Rivas-Martínez et al. 2001).

Biogeography:—The saltmarsh of Cordovilla belongs to the Castellano–Maestrazgo–Manchega province, namely to the Jumillano–Socovense district of the Manchego biogeographical sector (sensu Rivas-Martínez et al. 2001), to which Limonium tobarrense should be considered as a narrow endemic.

Reproductive features:—All examined individuals of Limonium tobarrense showed the pollen-stigma combination “B”, which corresponds to a self-incompatible type including pollen grains with finely reticulate exine and papillate stigma ( Erben, 1979) ( Fig. 3 ). Pollen irregularities are frequent and basically concerned shape and size. Together with typically trimorphic (3-, 4- and 5-colpate) and morphologically normal grains, other smaller and abnormally colpate grains (about 5–10%) occur. According to the obtained data, L. tobarrense can be regarded as an agamospermous species. Chromosome number counts are still needed to support this conclusion.

Conservation status:—As the only population found (Cordovilla) includes about fifty reproductive individuals, and there is not available information about its temporal variation/fluctuation, we suggest labelling L. tobarrense as Critically Endangered [CR, criterion D] according to the IUCN (2012) categories. Nevertheless, monitoring the evolution of this population in the future is recommended to more accurately evaluate the conservation status of the newly described species.

Diagnostic key:—The key reported below is based on that of Erben (1993), to which the newly described species is added to facilitate further identification.

1. Inner bract 6.0– 6.5 mm long; spikelets 5.5–7.0 mm long; outer bract 4.0– 4.5 mm long; calyx 5.5–6.5 mm long .......... L. dufourii

- Inner bract less than 5 mm long; spikelets up to 6 mm long; outer bract less than 3 mm long; calyx less than 5.7 mm long ........ 2

2. Stems densely hairy in the lower 1/3 part; inner bract hairy at the apex; calyx up to 3.5 mm long ............................ L. tobarrense

- Stems hairless or shortly papillate in the lower 1/3 part; inner bract glabrous; calyx ≥ 4 mm ........................................................ 3

3. Outer bract 1.8–2.3 mm; calyx 4.1–4.8 mm .............................................................................................................. L. girardianum

- Outer bract 2.4–2.9 mm; calyx 4.9–5.7 mm ......................................................................................................................... L. grosii

Figures

FIGURE 2. Limonium tobarrense J.Moreno, Terrones, M.A.Alonso, Juan & M.B.Crespo (holotype: ABH-71924). (a) habit; (b) basal rosette leaves; (c) spikelets; (d) outer bract; (e) middle bract; (f) inner bract; (g) flowering calyx; (h) fruiting calyx.

FIGURE 3. Limonium tobarrense. (a) Pollen grain type B (finely reticulate); (b) stigma type “papillate”.