Primula subpyrenaica Aymerich, L.Sáez & López-Alvarado, 2014

Aymerich, Pere, López-Alvarado, Javier & Sáez, Llorenç, 2014, Primula subpyrenaica (Primulaceae) a new species from the Pyrenean range (south-western Europe), Phytotaxa 163 (2), pp. 77-90 : 85-87

Primula subpyrenaica Aymerich, L.Sáez & López-Alvarado , sp. nov. ( Fig. 5 )

Primula subpyrenaica is morphologically similar to P. lutea and P. auricula , but differs by the following features: herbaceous bracts, instead of scarious in P. lutea and P. auricula ; longer bracts (2)6 – 15(19) mm long (average 8.4 mm), than in P. lutea and P.auricula , (0)2 – 4(6) mm long (average 3 mm); fragrant leaves, yellowish to brownish when pressed, while leaves are typically odourless and green in P. lutea and P. auricula .

Type : — SPAIN. Barcelona: Berguedà, Southern Pre-Pyrenees, Serra de Picancel, Pic de Salga Aguda , conglomerates, 1080 m, 31 TDG1364 , 20 April 2012, P. Aymerich, J. López-Alvarado & L. Sáez LS-7322 (holotype BC! , isotype MA! ).

Perennial plant, evergreen, farinose. Rhizome ascending to be erect and stout. Leaves 4.7 – 15.0 × 2.5 – 7.1 cm, forming a rosette (old leaves persistent at the base of the rosette), winter-dormant, scented, usually broadly obovate, sometimes oblong-lanceolate, obtuse or rounded at apex, tapering at the base into the petiole, subfleshy, efarinose, covered with glandular hairs 0.14 – 0.28 mm long (average 0.2 mm); midrib broad and conspicuous below; lateral veins more or less inconspicuous; leaf margin usually irregularly deep dentate at the upper 1/2 – 2/3 of its length (teeth up to 3 mm long), sometimes obscurely crenate; petiole broad and winged, half as long as the blade. Scape 1.3 – 12.2 cm at flowering, tall, usually stout, slightly hairy, 4 – 17 flowered; bracts 2 – 19 mm long (typically> 6 mm, average 8.4 mm), ovate to oblanceolate, herbaceous, sometimes irregularly dentate; pedicels 2 – 16 mm long, sparsely, hairy, usually farinose. Calyx 4 – 8.5 mm long at flowering (average 6.5 mm), narrowly campanulate, sparsely hairy, usually farinose, cut to below one half of its length; calyx teeth 1.5 – 3.5 mm long at flowering (average 2.3 mm), ovate to triangular, obtuse, sometimes acute. Corolla 14 – 22 mm long (average 18.8 mm), funnel-shaped, deep yellow, with a band of white farina around the mouth within; limb 1.5 – 2.5 cm in diameter; corolla lobes 5 – 10 mm long (average 7.1 mm), broadly obcordate, emarginate; tube 7.7 – 15.5 mm long (average 11.8 mm). Flowers scented, distylous; in short-styled (thrum) flowers anthers 1.4 – 2 mm long (average 1.7 mm), inserted above middle of tube, and style c. 2.5 – 3.7 mm long (average 3.1 mm); in long-styled (pin) flowers anthers 1.4 – 2.1 mm long (average 1.8 mm) subsessile, inserted 1 – 2 mm above the base of the tube, and style 8.2 – 10.5 mm (average 9.2 mm) long. Pollen grains 12.5 – 16.2 µm in diameter (average 14.8 µm). Capsule 5 – 6.5 × 4 – 5.5 mm, subglobose, dehiscing by 5(6) longitudinal valves. Seeds 0.7 – 1.3 mm in diameter (average 0.9 mm), irregularly polyhedral, with more or less prominent edges, papillose, dark brown.

Etymology:— The prefix sub - refers to the lower elevation of the ranges that make up the southern Pre-Pyrenean system, of which Serra de Picancel is part.

Distribution and ecology:— Currently, Primula subpyrenaica is restricted to Serra de Picancel, a low mountain range at the southern edge of the Catalan Pyrenees that runs 12 km east to west, with its highest peak at 1172 m. The new species was found in discontinuous patches distributed along the central and central-eastern sector of Serra de Picancel. Currently 12 patches are known, always separated by less than 500 m, and with a maximum distance of 3.7 Km between the more extreme patches. The number of basal rosettes (ramets or potential individuals) is several thousands. It has been looked for in nearby ranges with suitable habitats as far as 15–20 km away, but unsuccessfully to date.

The species grows on basic rocks (conglomerates) at elevations ranging from 790 to 1100 m along with Sesleria albicans Kit. ex. Schultes (1814: 216), Ramonda myconi (L.) Reichenbach (1831: 388), Saxifraga longifolia Lapeyrouse (1801: 26) and a number of moss species ( Aymerich et al., 2012). The surrounding vegetation consists of forests of Pinus sylvestris Linnaeus (1753: 1000) and Quercus ilex Linnaeus (1753: 995) ; mean annual rainfall is ca. 900–1000 mm, with marked inter-annual variation.

Conservation status:— To date, the species with the narrowest distribution within subsect. Euauricula, a group with a high number of narrow endemics (7 species of 15 as stated by Zhang et al., 2004) was P. recubariensis Proser & Scortegana (1998: 28) , a species described two decades ago restricted to one pre-Alpine massif in Italy (Proser & Scortegagna, 1998). Primula subpyrenaica has now become the species with the narrowest distribution. Despite this, Aymerich et al. (2012) considered that these populations, now regarded as P. subpyrenaica , are not under threat, due to the high number of mature individuals (ramets) and the lack of evidence of current threats; thus, the proposed IUCN (2001) category is NT (Near threatened).

Identification key:— We propose the following key to distinguish between the yellow-flowered species of Primula sect. Auricula :

1. Plants summer-dormant; leaves efarinose; seed coat smooth; bracts foliose, 10−25 mm long; calyces 7–11 mm, with acute lobes; corolla lobes ca. 5 mm. .................................................................................................................................. P. palinuri

- Plants evergreen or winter-dormant; leaves efarinose or farinose; seed coat papillose; bracts membranous or foliose, 1–19 mm long; calyces 2.5−8.5 mm, with obtuse (rarely subacute) lobes; corolla lobes typically> 5 mm. .................................. 2

2. Bracts foliose, typically> 6 mm long (2–19 mm); calyces typically> 5 mm (4–8.5 mm); leaves efarinose, yellowish brown when dry (sometimes yellowish green); leaves fragrant ................................................................................. P. subpyrenaica

- Bracts scarious, typically <4 mm long (1–6 mm); calyces typically <5 mm (1–6 mm); leaves efarinose or farinose, green when dry; leaves ordinarily not fragrant ................................................................................................................................ 3

3. Leaves narrowly obovate or lanceolate, efarinose or almost efarinose, grey green when dry; glandular hairs typically <0.2 mm long; flowers light yellow ...................................................................................................................................... P. lutea

- Leaves broadly obovate, often farinose, green when dry; glandular hairs typically>0,2 mm long; flowers dark yellow...... ................................................................................................................................................................................. P. auricula

Figures

FIGURE 5. Primula subpyrenaica sp. nov. A: whole plant (holotype); B: leaves; C: detail of seeds. Drawn by L. Sáez.