Edraianthus canescens D. Lakušić, Niketić & Stevanović, 2013

Lakušić, Dmitar, Niketić, Marjan, Rakić, Tamara & Stevanović, Vladimir, 2013, Edraianthus canescens (Campanulaceae), a new species from the Central Balkan peninsula, Phytotaxa 118 (1), pp. 22-28 : 23-27

Edraianthus canescens D. Lakušić, Niketić & Stevanović , sp. nov. Figs. 1 & 2.

— E. serbicus sensu Šmarda (1968: 45)

— E. graminifolius „ jugoslavicus “ sensu Stefanovi ć et al. (2008: 470)

Type: — SERBIA. W Serbia : Ov č arsko-Kablarska gorge, foothill of Mt. Kablar, Orlove stene, rock crevices, limestone, 43°54.362' N, 20°12.060' E, 308 m, 16 May 2008, D. Lakuši ċ 26617 (holotype: BEOU!, isotypes: BEOU!, NHMR!) .

Whole plant densely greyish hirsute, closest to E. graminifolius , from which it differs by the indumentum on basal leaves (densely hirsute and greyish on both sides of leaves vs. glabrous with ciliate-fimbriate margins or fine deflexed-pilose on both sides of leaves), trichome orientation (trichomes raised directed to the leaf apex, or orientated in all directions except towards the leaf base vs. trichomes raised directed only to the leaf base) and particular capsule dehiscence (capsule with basal lateral porose dehiscence vs. capsule with irregular apical rupture dehiscence).

Caespitose perennial with herbaceous stems. Rhizome stout, somewhat woody, with a branched caudex. Stem simple (4−)9−17(−22) cm, erect to ascending, leafy, densely hairy, with a nested like structure of the dense dried leaves at the base; dried stems remain on the plants for several years. Leaves narrowly linear, with flat margin, pointed at the top, densely greyish hirsute on both leaf sides, entire, densely covered with raised slightly curved hairs directed to the leaf apex, or orientated in all directions except towards the leaf base, hairs (0.2−)0.3(−0.5) mm long; rosette leaves 50−97(−129) × (1.3−)1.7−3.2(−4) mm, rigid end erect, form a globular cushion from which several stems grow out; cauline leaves sessile, (17−)27−51(−71) × (2.3−)3.2− 6.2(−9) mm, usually with a wide amplexicaul base. Involucral bracts 6−12(−19), shorter or equal with the flower, densely hirsute and greyish above, entire, rarely slightly denticulate, whitish to pale green at the base, densely subtend the flower; inner bracts lanceolate to ovate-oblong, (8.3−)13.7−21.3(−27) × (4.3−)6−9.5(−13) mm; outer bracts subovate-lanceolate, slightly attenuate, (17.9−)18.7−32.5(41) × (4.5−)7.0−11.2(−14) mm. Inflorescence with (3−)5−9(−11) subsessile flowers in a terminal cluster. Calyx greyish to pale green, hirsute, (4.3−)5.0−6.8(−7) mm in diameter; calyx teeth narrowly lanceolate, pointed at the top, 2−3 times as long as the ovary, (6.2−)8.0−11.2(−14) × (0.7−) 0.8−1.2 mm, commonly without setulose or ciliate appendages. Corolla narrowly campanulate, violet, glabrous, hirsute on veins and corolla lobes, (18.8−)21.1−28.5(−36) × (12.3−)13.6−18.3(−20) mm; corolla lobes (6.3−)8.3−12.2(−15) × (4.9−)6.1−8.3(9) mm. Style (18.9−)20.8− 26.2(−33) mm long, 2−3-lobed. Stamens 5, inserted on disc; anthers (5.9−)6.3−8.8(−11) mm long; filaments 0.9−2.0(−3.0) mm long, in lower part distinctly dilated to deltoid-shaped 1−4 mm long structure. Capsule pale brownish, opening by basal lateral pores and with irregular apical rupture; axicorn very strong and prominent, with two strong terminal lobes. Seeds numerous, elliptic-ovate, light brown 1.4−1.8 × 0.8−1.1 mm.

Etymology: —The specific epithet is derived from the main and prominent characteristic of the plant⎯densely hirsute and greyish indumentum on the stem as well as on the both sides of leaves and involucral bracts.

Chromosome number: —2n = 32 (counted on plants from locus classicus).

Distribution and ecology: — Edraianthus canescens is distributed in a very narrow area restricted to the Ovčarsko-Kablarska gorge only (western Serbia). Closest populations of the E. graminifolius complex ( E. jugoslavicus ) are situated c. 30 km west-, south- and northwards from the type locality ( Fig. 3 ). E. canescens belongs to the eastern Dinaric (Illyrian) local endemic species.

The new species primarily inhabits the calcareous south-facing exposed rocky crevices at elevations between 300 and 750 m. Edraianthus canescens is one of the most abundant rock dwellers growing together with Asplenium ruta-muraria L., A. trichomanes L., Leontodon crispus DC. ex Nyman , Helianthemum canum (L.) Baumg., Micromeria thymifolia (Scop.) Fritsch , Scabiosa graminifolia L., Seseli rigidum Waldst. & Kit. , Genista triangularis Willd. etc. Except in the rocky crevices, rare individuals of E. canescens were recorded in vegetation of the calcareous screes, growing together with Carex humilis Willd. ex Kunth , Euphorbia subhastata Vis. & Pančić , Seseli rigidum Waldst. & Kit. , Fraxinus ornus L., Jurinea mollis Rchb. , Leontodon crispus DC. ex Nyman , Clematis vitalba L., Silene vulgaris (Moench) Garcke , Sesleria juncifolia Suffren s.l., Laserpitium siler L., Lembotropis nigricans (L.) Griseb., etc.

Conservation status: — Edraianthus canescens is known only from its type locality. Its population size is estimated to be less than 2000 mature individuals while the area of occupancy is smaller than 1 km 2. Therefore according to the IUCN (2001) Criteria it should be regarded as Critically Endangered, CR B1 i, ii, iv; B2a.

Additional specimens examined (paratypes): — SERBIA. W Serbia : Ovčarsko-Kablarska gorge, in rupium fissuris prope Ovčar Banja ad radices montis Kablar, solo calcareo, 300 m. s.m, 20 May 1974 , E. Mayer, D. Trpin , T. Wraber 39602 ( LJU!); Ovčarsko-Kablarska gorge, limestone rocks, 24 August 1978 , V. Nikoli ċ , N. Dikli ċ , S. Mladenovi ċ ( BEO!); Ovčarsko-Kablarska gorge, limestone rocks, 21 Jun 2004 , M. Niketi ċ, 20040606/017 ( BEO!); Mt Kablar, screes in stands of Ostrya carpinifolia woodland, limestone, 12 Jun 2005 , M. Niketi ċ 20050602/008 (BEO!), M. Niketi ċ 19958 ( BEOU!); Ovčarsko-Kablarska gorge, Orlove stene (“ Eagle’s cliffs”), 43°54.362' N, 20°12.06' E, Asplenietea rupestris , limestone, 308.2 m, 17 July 2006 , V. Stevanovi ċ, D. Lakuši ċ 20960 ( BEOU!); Ovčarsko-Kablarska gorge, Orlove stene (“ Eagle’s cliffs”),, 43°54.362' N, 20°12.06' E, Asplenietea rupestris , limestone, 308.2 m, 17 May 2007 , D. Lakuši ċ, T. Raki ċ, 24020 (BEOU!)).

Discussion:—The newly described species, Edraianthus canescens belongs to the E. graminifolius complex (sensu Stefanović et al. 2008) which includes plants with long linear basal leaves, sessile flowers, either solitary or in terminal cluster, closely subtended by large leaf like or ovate bracts, narrowly lanceolate calyx teeth, which are pointed at the top, 2-3 times as long as the ovary and commonly with setulose or ciliate appendages; leaves and bracts are ciliate-fimbriate at margins only or fine deflexed-pilose on both sides, with hairs directed to the leaf base.

Edraianthus canescens is easily distinguished from its closest relatives in the E. graminifolius complex by the trichome orientation and the particular capsule dehiscence (Tab. 1, Fig. 2 ).

An exceptionally dense greyish-green indumentum of leaves, stems, bracts and calyx, at first glance, is the most striking feature of the new species. However, unlike all the other representatives of the complex E. graminifolius , which have trichomes raised directed to the leaf base, the new species has trichomes raised directed to the leaf apex, or orientated in all directions, except towards the leaf base. The significance of trichome orientation in differentiating Edraianthus taxa has been recently discussed by Surina et al. (2009).

In addition, unlike other representatives of the E. graminifolius complex with pronounced indumentum (specially in the southern distribution range⎯ E. siculus Strobl 1883: 551 , E. australis ( Wettstein 1887: 201) Lakušić ex Meyer 2011: 154 , E. horvatii Lakušić 1974: 44 , E. pubescens Meyer 2011: 156 whose indumentum density may vary substantially within the same population (from densely hairy to completely glabrous plants), all plants from the Ovčarsko-Kablarska gorge have a very dense gray indumentum.

Molecular data indicate that plants from the Ovčarsko-Kablarska gorge are clearly distinguished from other taxa with exceptionally dense indumentum from Southern Balkan and Sicily. Parsimony bootstrap supports (BS) and Bayesian posterior probabilities (PP) strongly indicates that E. horvatii (S. Macedonia ⎯BS 89 %, PP 100 %), E. australis (S. Greece ⎯BS 66 %, PP 100 %) and E. siculus (Sicily⎯BS 85 %, PP 100 %), are phylogenetically separated from the plants from the Ovčarsko-Kablarska gorge, representing “ molecularly distinct lineages ” (Stefanović et al. 2008).

The capsule with the basal lateral porose dehiscence is undoubtedly the most important character that separates the new species from all other representatives of the E. graminifolius complex. The importance of fruit dehiscence in Edraianthus and its position within Campanulaceae is observed and recently discussed in detail by Stefanović et al. (2008). In that publication it was stated that in some individuals of Edraianthus some fruits open apically while other fruits open laterally, reminiscent of those found in Campanula . Taking into account that different states of capsule dehiscence can be found even within a single individual, it is clear that the taxonomic significance of the capsule dehiscence is limited for the higher-level family classification in Campanulaceae . Basal pores and prominent axicorn are extremely rare features, registered only in two strictly endemic Edraianthus species ( E. tare Lakušić 1987: 108 from sister group of the E. graminifolius complex and E. glisicii Č ernjavski & Soška 1937: 88 from E. serpyllifolius complex, according to Stefanović et al. 2008). These characters have therefore high taxonomic significance at species level.

Furthermore, the overall habitus of the plants with a nested like structure of dense dried leaves at the base and dried stems that remain on the plants for several years, is a very specific morphological feature of E. canescens .

In addition to the above-described morphological characteristics, the plants from the Ovčarsko-Kablarska gorge are separated from other representatives of the E. graminifolius complex from the central Balkans by the shape of the bracts. Correspondence Analysis (CA) showed that, in respect to the qualitative characters analyzed, E. canescens is significantly distinct from all studied populations within the E. graminifolius complex (Rakić et al. 2012). Except for the extremely dense indumentum, resulting in the greyish color of the plant surface, these plants are characterized by the broad and short apex of the involucral bracts.

Taking all this into account, we conclude that the plants from the Ovčarsko-Kablarska gorge are morphologically clearly defined and can be easily distinguished from all the other species from E. graminifolius complex, and hence, they merit rank of new species.

Figures

FIGURE 1. Edraianthus canescens D. Lakušić, Niketić & Stevanović, sp. nov. (from the holotype). A. Habitus. B. Rosette leaf. C. Bracts of flowering capitula. D. Calyx. E. Anther. F. Style. G. Corolla. H. Capsule with axicorn (linedrawing V. Stevanović).

FIGURE 2 Edraianthus canescens D. Lakušić, Niketić & Stevanović, sp. nov. (from the locus classicus). A. Habitus. B. Inflorescence with involucral bracts. C. Flowers with calyx teeth. D. Rosette leaves. E. Cauline leaves. F. Inflorescence. G.. Capsules with basal lateral pores and axicorns. H. Capsule with axicorn. I. Seed. (photo D. Lakušić).

FIGURE 3. Distribution of taxa of the Edraianthus graminifolius complex in C. &. S Balkan Peninsula. Arrow indicates stenoendemic range of E. canescens. Country abbreviations: GR: Greece, AL: Albania, MA: Macedonia, BU: Bulgaria, SR: Serbia, BH: Bosnia and Hercegovina.