Valeriana praecipitis A.E. Villarroel & Menegoz, sp. nov.

Villarroel, Alejandro E., Menegoz, Kora, Quesne, Carlos Le & Moreno-Gonzalez, Ricardo, 2022, Valeriana praecipitis (Caprifoliaceae), a species new to science and endemic to Central Chile, PhytoKeys 189, pp. 81-98 : 81

Valeriana praecipitis A.E. Villarroel & Menegoz, sp. nov.

Figures 2 , 3 , 4

Type.

Chile. Nuble Region , Punilla Province, San Fabián de Alico, Laguna Añil, crevices and small terraces of granite cliffs , 1724 m elevation, 36°32'00.8"S, 71°23'36.1"W, 7 January 2020, A.E. Villarroel & E. Ponce s.n., (holotype SGO!); 1724 m elevation, 36°32'00.8"S, 71°23'36.1"W, 3 February 2021, A.E. Villarroel & R. Neira (paratypes EIF!, JBN!); 1650 m elevation, 36°32'2.28"S, 71°23'26.62"W, 7 December 2020, K. Menegoz & G. Ossa (paratypes CONC!) (Fig. 2 ). Laguna Añil is the only site where herbarium specimens were collected.

Diagnosis.

The habit and macro-morphology of Valeriana praecipitis is similar to Valeriana philippiana , but differs by its height (including flower stem) that can reach 65.5 cm (vs. 20 cm), rhizome woody, reaching more than 30 cm long and up to 20 mm diameter (vs. semi-woody, to 14 cm long, to 8 mm diam.), basal leaves pinnatisect to pinnatipartite, up to 26 cm long (vs. pinnatilobed to pinnatisect, to 8 cm long), petiole glabrous (vs. pubescent), lobes 1-35 mm long, 1-24 mm wide (vs. 4-8 × 3-7 mm), upper leaves oblanceolate, 14-40 mm long, 5-19 mm wide, margin entire to irregularly undulate or sinuate, (vs. oblong, 6-10 × 3-5 mm, entire), bracts oblanceolate to oblong, up to 20 mm long (vs. oblong, to 7 mm long), bracteoles spathulate to oblong, 3-7 mm long, entire (vs. oblong, 2.5-4.5 mm, erose), inflorescence a relatively diffuse thyrse or compound dichasial cyme (vs. dense compound dichasial cyme, contracted), corolla up to 4.5 mm long (vs. up to 4 mm), stamens 3 mm long (vs. 2 mm), stigma 0.2 mm long (vs. 0.5 mm), growing on cliffs that remain humid all-year (vs. well-drained rocky soils), and endemic to the Ñuble Region (vs. in Chile, V. philippiana can be found in Los Lagos, Aysén and Magallanes Regions) (Table 1 ).

Description.

Perennial herb, hemicryptophyte, erect or lax when cliff-hanging, simple or branched from the upper part of the taproot, 4-25 cm tall (26-65.5 cm with inflorescence), 4-28.5 cm wide. Rhizome is dark brown, thick, circular, simple, sometimes branched, reaching more than 30 cm long, 8-20 mm diameter, vertical to lateral, sometimes stoloniferous, woody, tortuous, rough, fetid. Secondary - tertiary roots, numerous, located in the first 3 cm of the upper part of the taproot. Stem merging into the taproot, 3.5-6 mm diameter, with short internodes, forming a basal rosette with 9-25 whorled leaves. Basal leaves deciduous, silvery-green turning yellow-brown at the end of summer, simple, petiolate, pinnatisect, sometimes becoming gradually pinnatipartite at the apex (mainly young leaves), oblong, generally symmetric; blade 3-16 cm long (4-26 cm with petiole), 1.5-6.3 cm wide, glabrous, fleshy, with reticulated veins; petiole green turning purple towards the base, canaliculated, up to 14.5 cm long, 3-13 mm wide at the base, 2-7 mm wide at the blade base, entire, glabrous, midrib visible; lateral lobes opposite to subopposite, superimposed, orbicular to obovate, base attenuate, apex rounded to retuse, margin entire to slightly undulate and involute, 6-26 per blade; larger lobes located in the centre of the blade, 9-35 × 7-22 mm; smaller lobes located at the base of the blade, 1-15 × 1-8 mm; terminal lobe orbicular to obovate, 6.5-23.5 × 6-24 mm, base attenuate, apex rounded to obtuse, occasionally retuse, margin entire to irregularly undulate or lobed. Inflorescence a relatively diffuse thyrse or terminal compound dichasium, sometimes corymboid. Floral stem purple at the base, light green towards the flowers, erect, circular, 28.6-60 cm long, 3.5-6 mm diameter at the base, gradually thinner towards the flowers (1.5-2.9 mm), striated, 5-9 internodes (their length decreasing from base toward the apex), branched in the upper half (2-27 cm long) with 1-6 lateral ascending branch pairs (forming partial inflorescences). Upper leaves green, simple, sessile, oblanceolate, 14-40 × 5-19 mm, opposite, decussate, arranged every 2.7-13.5 cm on the flower stem, leaves’ size decreasing from base toward the inflorescence, margin entire to irregularly undulate or sinuate, base decurrent, apex acute to rounded, occasionally retuse, glabrous, less fleshy than basal leaves, reticulated veins. Bracts green, simple, sessile, oblanceolate to oblong, 7-21.2 × 1-7 mm, decreasing in size towards the inflorescence, opposite, decussate, margin entire, base decurrent, apex variable (acute, rounded or retuse), glabrous, less fleshy than upper leaves, reticulated veins. Bracteoles green, sometimes turning purple towards the apex, simple, sessile, spathulate to oblong, 3-7.5 × 0.5-2 mm, decreasing in size towards the inflorescence, opposite, decussate, margin entire, base decurrent, apex rounded to retuse, glabrous, less fleshy than upper leaves. Flowers hermaphrodite, pentamerous, sessile; calyx green and purple at the top, inconspicuous, fused segments forming a wavy ring, 0.3 mm, pubescent, adnate to the infer ovary, accrescent and persistent on fruit modified into feathery structures forming the pappus; corolla 5, fused petals, white, although buds sometimes with purple-pink tinges, infundibuliform, glabrous, 4-4.5 mm wide; corolla tube 3.5-4.5 mm long, base slightly gibbous; corolla lobes oblong to obovate, 1-1.5 × 1-1.7 mm, perpendicular or slightly inclined in relation to the corolla tube; stamens 3, white, filiform, 3 mm long, exerted, attached in the lower third of the tube; anthers light yellow, ellipsoid, bithecal, dorsifixed, deciduous; ovary inferior, green, tricarpellate, trilocular with 1 fertile locule and 2 incipient sterile locules; style 1, white, filiform, 2.2 mm long; stigma trifid, lobed, laminate to lamellate, less than 0.2 mm. Fruit an achene, yellow-green at the base, turning purple towards the apex, ellipsoid, triquetrous, 3 × 1 mm, pubescent, longitudinally striated on one face, calyx persistent, pappus plumose, 0.5 mm diameter at base, bristles 11, purple-reddish colour, 3.5 mm long, with hairs 0.5 mm long.

Etymology.

The specific epithet refers to cliff faces inhabited by these plants. The name means " Valeriana of cliffs" (latin praeceps = steep place, precipice, dangerous; genitive Valeriana praecipitis ).

Phenology.

Flowering from November to December; fruiting from January to February.

Distribution and habitat.

Endemic to the Andean ranges of the Ñuble Region, Chile (Fig. 1A, B ). Specifically, 5 sites are known so far (Fig. 1C ): Laguna Añil (1724 m elevation, 36°32'00.8"S, 71°23'36.1"W; 1650 m elevation, 36°32'2.28"S, 71°23'26.62"W); Cuernos del Valiente (1530 m elevation, 36°27'46.31"S, 71°29'14.41"W), Cordillera del Malalcura (1700 m elevation, 36°32'0.23"S, 71°30'7.59"W), Laguna del Florido (1980 m elevation, 36°30'55.07"S, 71°14'1.20"W), and the last at Laguna del Huemul (1970 m elevation, 36°52'40.11"S, 71°29'6.33"W, this locality was found by Eitel Thielemann). The maximum distance between the sites is 38 km. The species usually grows at high elevations (1530-1980 m), in crevices and small terraces of south, southeast and southwest facing cliffs (Fig. 5 ). Due to snow melting and low sun exposure, these sites remain humid during the dry season. Two closest weather stations, Punilla (840 m elevation) and Caracol (725 m elevation), indicate that the average annual temperature is 11.8 °C and the average total annual precipitation 2150 mm for the period 1965-2012 ( DGA 2018). Although at a lower elevation than V. praecipitis altitudinal range, a private pluviometer in the village of San Fabián de Alico (447 m elevation) recorded an annual average precipitation of 1399 mm for the period 2017-2020 (Covarrubias J.C., pers. comm.). In addition, to get a better impression of the local conditions during year 2020 temperature and humidity data loggers HOBO U23 Pro v2 (Onset Computer Corporation, Massachusetts, USA) registered an average annual temperature of 6.7 °C, with a minimum of -2.8 °C, a maximum of 24.1 °C, and an average humidity 60.12% at Laguna Añil; and an average annual temperature of 8.7 °C, with a minimum of -4.5 °C, a maximum of 24.9 °C, and an average humidity of 66.39 % in Cordillera del Malalcura.

Associated vegetation.

From a phytogeographical point of view, Valeriana praecipitis is part of two vegetational formations and three vegetation belts ( Luebert and Pliscoff 2017). The vegetation formation at Laguna Añil, Cuernos del Valiente and Cordillera del Malalcura corresponds to Deciduous forest, and the vegetation belt to the Andean temperate deciduous forest of Nothofagus pumilio (Poeppig & Endlicher) Krasser ( Nothofagaceae ) and Azara alpina Poeppig & Endlicher ( Salicaceae ) (Fig. 5A, B ); the vegetation formation in Laguna del Florido corresponds to the Altitude low scrub, and the vegetation belt to the Andean Mediterranean low scrub of Laretia acaulis (Cav.) Gillies & Hook. ( Apiaceae ) and Berberis empetrifolia Lam. ( Berberidaceae ) (Fig. 5C ). Finally, Laguna del Huemul is part of the Altitude low scrub formation, and the Temperate Andean low scrub of Discaria chacaye (G. Don) Tortosa ( Rhamnaceae ) and Berberis empetrifolia vegetal belt.

Our field observations in Laguna Añil (1724 and 1650 m elevation) indicate a total of 45 species associated with Valeriana praecipitis . Some of these species include: Chiliotrichum diffusum (G. Forst.) Kuntze, Senecio spp. ( Asteraceae ), Berberis empetrifolia , Maytenus disticha (Hook.f.) Urb. ( Celestraceae ), Desfontainia fulgens D. Don ( Columelliaceae ), Empetrum rubrum Vahl ex Willd., Gaultheria sp., G. poeppigii DC., G. pumila (L.f.) D.J. Middleton, G. tenuifolia (Phil.) Sleumer ( Ericaceae ), Escallonia alpina Poepp. ex DC., E. rubra (Ruiz & Pav.) Pers., Rayenia malalcurensis Menegoz & A.E. Villarroel ( Escalloniaceae ), Luzula sp. ( Juncaceae ), Myrceugenia chrysocarpa (O. Berg) Kausel, Myrteola nummularia (Poir.) O. Berg ( Myrtaceae ), Nothofagus obliqua (Mirb.) Oerst., N. pumilio ( Nothofagaceae ), Codonorchis lessonii (Brongn.) Lindl. ( Orchidaceae ), Ourisia sp., O. coccinea (Cav.) ( Plantaginaceae ), Chusquea montana Phil. ( Poaceae ), Saxifraga magellanica Poir. ( Saxifragaceae ), Quinchamalium chilense Molina ( Schoepfiaceae ).

Conservation status.

Valeriana praecipitis is assessed here as Endangered (EN) under the IUCN categories following criteria B2ab(iii). Criterion B2 was selected because its area of occupancy is <500 km2 (estimated at 20 km2). Criterion “a” was selected because it is known to exist in two locations (Fig. 1C , north and south of Ñuble river). Criterion “b(iii)” was selected because there is a projected decline in the area, extent, and quality of habitat. High Andean plants are very sensitive to global warming, given that migration is limited by the lack of connectivity between summits and its reduced areas on the top, additionally, the 2010-2017 mega-drought in Central Chile, resulted in a significant reduction in precipitation and snow cover - the most severe during the last 1000 years - together with an increase in temperatures for the last decade ( Garreaud et al. 2017; Cordero et al. 2019). One of the climate change model scenarios projects an increase of at least 1 °C of the mean temperature for the next 30 years, plus a decrease in winter precipitations of about 30% at the end of the century ( Bozkurt et al. 2017). Valeriana praecipitis extent of occurrence is ~555 km2 (Fig. 1B ). The species is not present in any protected area in Chile, and it is not protected by law.

Figures

Figure 1. Distribution maps of Valeriana praecipitis A Chile B Nuble Region C sites of V. praecipitis (yellow stars) and extent of occurrence (red line).

Figure 2. Holotype of Valeriana praecipitis.

Figure 3. Valeriana praecipitis A habit B, C fruit D detail of flower E stigma F bracteole G bract H upper leave. Drawn by Aron Cadiz-Veliz.

Figure 4. Valeriana praecipitis A, B plants growing in natural habitat C rhizome, secondary-tertiary roots D basal leaves with lobes detail E petioles F floral stem, corymboid inflorescence G floral stem, thyrse inflorescence H upper leaves I, J detail of flowers (stamens, style) K bracteoles, ovary, calyx L dry inflorescence, bracts, bracteoles M fruit, pappus. Photographed by Alejandro E. Villarroel and Kora Menegoz.

Figure 5. Habitat of Valeriana praecipitis (red arrow indicates the species) A, B Laguna Anil C Laguna del Florido. Photographed by Alejandro E. Villarroel and Kora Menegoz.