Goniolimon africanum Buzurović, Bogdanović & Brullo, 2018

Buzurović, Uroš, Bogdanović, Sandro, Brullo, Salvatore, Niketić, Marjan & Tomović, Gordana, 2018, Goniolimon africanum (Plumbaginaceae), a new endemic species from North Africa, Phytotaxa 349 (3), pp. 287-297 : 288-294

Goniolimon africanum Buzurović, Bogdanović & Brullo sp. nov. ( Figs. 1–2 )

Type:—AFRICA. Algeria: Batna, sur les collines arides, 15 July 1853, B. Balansa 814 (sub Goniolimon tataricum Boiss. / Statice tatarica L., Goniol. luteolus, Coss. et DR. ! olim. / Herb. E. Cosson) (holotype P 05388232!; isotypes P 05117905!, BM!, MANCH!, MPU 243820!, W 99191!, W 278982!, WAG 1169431!).

Diagnosis: — Species a Goniolimone tatarico similis sed usque ad 25 cm alta, foliis glaucescentibus, spathulatis vel oblanceolato-spathulatis, 2–10 cm longis, 4–14 mm latis, acuminato-aristatis, 1-nervatis, scapo striato-costato, pubescenti, spicis 8–20 mm longis, spiculis 1(2)-floris, ad 5–7 pro centimetro dispositis, bractea exteriore 2.3–2.5 mm lata, cuspide 1.5–2.5 mm longa, bractea media 4–5 mm longa, bractea interiore 4.5–5.5 mm longa, cuspide centrale 2–2.5 mm longa, cuspidibus lateralibus 0.7–1.5 mm longis, auriculis absentibus, calycis tubo dense pubescenti, nerviis fere ad apicem loborum attingentibus, lobis 1–1.3 mm longis.

Description: —Plant perennial, forming a sub-shrub, 7–20(25) cm high, with 1–3 erect stems and a robust taproot. Caudices 2–5 cm long, branched, living leaves in rosettes at apices and branches covered by dry leaf remnants. Leaves glabrous, coriaceous, rigid, glaucescent, minutely dotted, 2–10 cm long and 4–14 mm broad, spathulate to oblanceolate-spathulate, acuminate-aristate mucronate, 1-nerved, with margin narrowly hyaline and often undulate, gradually tapering into the petiole. Stems scabrous-pubescent, rigid, striate-ribbed, 6–15(20) cm long, branched in the upper part. Inflorescence densely branched, with branches curved, rigid. Spikes 8–20 mm long, straight. Spikelets 7–8 mm long, 1(2) flowered, densely arranged, 5–7 per cm. Outer bract 3.5–5.0 mm long and 2.3–2.5 mm wide, triangularovate, long cuspidate, mucronate at apex, pubescent, with narrow hyaline margin, with cusp 1.5–2.5 mm long. Middle bract membranous, 4–5 mm long and 1.5–1.8 mm wide, oblong, laterally gibbous, long cuspidate, mucronate at apex, pubescent in the central part and cusp. Inner bract oblong to oblong-rounded, 4.5–5.5 mm long and 2.2–2.5 mm wide, 3-cuspidate, mucronate at the apex, with central cusp 2.0– 2.5 mm long and lateral ones 0.7–1.5 mm long; margin membranous; hairy in the central part and cusps. Calyx 6.5–7.0 mm long, exceeding the inner bract by 2.5–3.5 mm; calyx tube densely pubescent, with 5 ribs reaching almost the lobe apex; lobes triangular, 1.0– 1.3 mm long, undulate at the margin ( Figs. 1–2 ).

Etymology: —The specific epithet “ africanum ” refers to Africa, where the species occurs.

Phenology: —Flowering from June to July.

Distribution and ecology: —Based on investigations of herbarium specimens and literature data, G. africanum is distributed in North Africa, currently limitedly to some localities in Algeria and Tunisia ( Fig. 4 ). In particular it occurs in north-western Algeria near the Chott Chergui (Saida) and in north-eastern Algeria in the neighbourhoods of Batna and Constantine, while in northern Tunisia it is localized in a small stand near Kesra (“Kessera”). This species grows in very arid territories characterized by sub-desert climate and is localized in sandy or rocky habitats, where it is a member of steppe grassland or halophilous shrubby plant communities.

Discussion: —According to literature (Battandier & Trabut 1882, 1902, Quézel & Santa 1963, Pottier-Alapetite 1981, Le Floc’h et al. 2010) populations of G. africanum were attributed to G. tataricum , although Cosson (1853), who was the first to collect this plant in Algeria during a botanical excursion in May 1852, considered it as a distinct species quoted by this author on the label of its herbarium sheets. Subsequent botanists (e.g. Balansa, du Colombier, D’Alleizette, Hénon, Warion, Joly, Bachelet, de la Perraudière, etc.), who collected this species in Algeria and Tunisia, identified it as G. tataricum . This determination has also been followed in the most recent Mediterranean floras ( Greuter et al. 1989, Domina 2011). Besides, it should be highlighted that E. Cosson carried out his excursions in Algeria together with B. Balansa, who collected much more material of this species, distributing his specimens to several European herbaria. Therefore, we have considered it opportune to choose these specimens as type material of G. africanum . Among the isotypes kept in W, we found that W. Wangerin in 1929 noted on a distinct herbarium label a new name “ Goniolimon collinum (Griseb.) Boiss. ssp. cossonii Wangerin ined.” that he proposed for this plant. This name remains a nomen nudum since it has never been published.

Regarding its taxonomic relationships, G. africanum is morphologically distinct from other known species of Goniolimon . In particular, it differs from G. tataricum ( Fig. 3 , Table 1) in its smaller size, leaves being 1-nerved (not pinnatinerved), shorter (2–10 cm vs 10–20 cm) and markedly acuminate-aristate mucronate (not obtuse and rounded), stems being pubescent and not winged (vs glabrous to sparsely puberulous and winged), spikes that are much shorter (0.8–2.0 cm vs 2.5–10.0 cm) and denser (not lax), 1(2)-flowered spikelets (not 2–3-flowered), outer bract that is narrower (2.3–2.5 mm vs 2.5–3.0 mm) with a longer cusp (1.5–2.5 mm vs 1.2–1.3 mm), a longer middle bract (4–5 mm vs 3.7–4.0 mm), a longer inner bract (4.5–5.5 mm vs 4.0– 4.5 mm) with longer cusps (2.0– 2.5 mm and 0.7–1.5 mm vs 1.4–1.7 mm and 0.6–0.8 mm) and auricles that are absent (not present), the calyx being pubescent only in the tube (not also on the ribs), and with ribs almost reaching the lobe apex (vs ribs not reaching the lobe base). A detailed morphological investigation of the known European species of Goniolimon ( Fig. 3 , Table 1), showed that G. africanum is well differentiated from them all. It shows a closer relation with G. sartorii , which is distributed in some Aegean islands and Attica ( Greece). The two species share some features (e.g. habit, colour, shape and size of leaves, short and dense spikes, spikelets 1-flowered), but several other significant characters distinguish these two species from each other. In particular, G. sartorii is characterized by a glabrous stem, spikes with 7–9 spikelets per cm, glabrous bracts, an outer bract with a shorter cusp, a shorter and wider inner bract, a shorter glabrous calyx with smaller lobes exceeding the lobe base. These two species have very similar ecological requirements, since they occur in arid environments, often characterized by saline soils. These habitats are represented by coastal sandy or rocky places for G. sartorii and by inland steppe sub-desert grasslands or salt lakes for G. africanum . A very similar ecology was observed also in G. incanum , which occurs in coastal sandy or rocky grounds and hilly xerophilous grasslands.

Additional specimens examined (Paratypes):— ALGERIA. Aïn Beïda, July, sine leg., sub. Goniolimon tataricum (MPU 243816!); Dunes du Chott, Tarf, July, sine leg. (MPU 243817!); Batna, 1911, Ch. D’Alleizette s.n., sub. Goniolimon tataricum Boiss. (CLF 173391!); plaine de Batna, Algèrie, 1854, du Colombier 175, sub. Goniolimon tataricum Boiss. (P 05388237!); Batna, s.d., A. Hénon s.n., sub. Goniolimon tataricum Boiss. (MPU 243814!); terrains salés près du Madracca près Aïn-Yagaert, cercle de Batna, prov. de Constantine, 17 June 1853, E. Cosson s.n., sub. Goniolimon tataricum Boiss. ( G. luteolus Coss. et Dr. ) (P 04026846!); dépressions des hauts plateaux à El May (Sahara Oranais), 02 July 1868, A. Warion s.n., sub. Goniolimon tataricum Boiss. (P 05388231!); plaines d’Alfa entre Krider et Beida, cercle de Saïda (Algérie), 30 May 1852, E. Cosson s.n., sub. Goniolimon luteolus (P 05388234!); Massif de Tafrent, Ouled Abd Ennour, prov. d. Constantine, 01-08 June 1912, Joly s.n., sub. Goniolimon tataricum (L.) Boiss. (MPU 243819!); Tafrent (Abd Ennour), (prov. d. Constantine), 17 June 1909, Joly s.n., sub. Goniolimon tataricum L. (MPU 243818!); El Beïda, 30 May 1852, E. Cosson s.n., sub. Goniolimon luteolus Coss. et Dr. (P 05388236!); cultivé HDR (Hortus Durieu, Bordeaux), 06 July 1855, Durieu s.n., sub. Goniolimon tataricum Boiss. , G. luteolus C. et Dr. olim. (P 05388235!); bords de l’Halloufa, 1883, Bachelet s.n., sub. Goniolimon tataricum (P 05388233!); plaine entre Morsot et Tebessa, prov. de Constantine, Algérie, 1864, V. Reboud s.n., sub. Goniolimon tataricum (P 05388233!, P 04026845!); Trubeau de Synhàn, cercle de Batna, province de Constantine, Algérie, 17 June 1853, H. de la Perraudière s.n. (MPU 243813!); Le long des sentiers du Djebel Dyr près Tebessa, 28 Juin 1864, V. Reboud, sub. Statice , Goniolimon tataricum (GRM s.n.!); Aïn Tamagra, avril-mai 1872, V. Reboud (GMR s.n.!).

TUNISIA. Falaises de la Kessera, 09 May 1944, Iserite? 28, sub. Statice sp. (MPU 243821!).

Figures

FIGURE 1. Diagnostic features of Goniolimon africanum. A. Habit. B. Leaves. C. Leaf apex. Illustration by S. Brullo based on type material (P 05388232!).

FIGURE 2. Diagnostic features of Goniolimon africanum. A. Spikelets. B. Spike. C. Calices. D. Open calyx. E. Outer bracts. F. Middle bracts. G. Inner bracts. Illustration by S. Brullo based on type material (P 05388232!).

FIGURE 3. Comparative diagnostic features of spikelets (A), calices (B) and inner bracts (C) for 1. G. africanum. 2. G. tataricum. 3. G. dalmaticum. 4. G. incanum. 5. G. heldreichii. 6. G. italicum. 7. G. besserianum. 8. G. sartorii. Illustration by S. Brullo.

FIGURE 4. Distribution of Goniolimon africanum in North Africa. Black circles—herbarium records; red circle—literature records; red/black circles—herbarium and literature records.