Nototriche antisanensis E. J. Trujillo, Muriel, Espinel-Ortiz & Romol., 2025

Trujillo, Emilio J., Espinel-Ortiz, David A., Romoleroux, Katya & Muriel, Priscilla, 2025, A new species of Nototriche (Malvaceae, Malvoideae) from the high Andes of Ecuador, PhytoKeys 261, pp. 1-12 : 1-12

Nototriche antisanensis E. J. Trujillo, Muriel, Espinel-Ortiz & Romol. sp. nov.

Figs 1 , 2 , 3 , 4

Diagnosis.

Nototriche antisanensis is morphologically most similar to N. jamesonii in having both surfaces of the leaf lamina covered by small stellate trichomes, triangular stipules and connate petals but the former differs from the latter in its cushion-forming (vs. prostrate shrubby) habit, dense (vs. lax) rosettes with 3 (vs. 9) lobes, free part of the stipule narrowly triangular with a 6: 1 proportion (vs. triangular with a 2: 1 proportion), sheath with both faces covered by stellate indumentum (vs. abaxial face glabrous), flowers with corolla tubes 1–2 mm (vs. 2.5–5 mm) long, anthers forming a globose head with a spherical 1: 1 proportion, 2–3 × 2–3 mm (vs. elliptic 2: 1 proportion, 3–5.5 × 2.2–3 mm); and a fruit with 11 (vs. 10) mericarps.

Type.

Ecuador • Napo: Cara oeste del volcán Antisana, alrededores de la Laguna de Santa Lucía, arenal en la cara norte del pico Antisanilla , 00°28.436'S, 78°11.407'W, 4325 m elev., 18 Jan 2025 (fl), E. J. Trujillo R. Barrera-Cabezas, G. Núñez & N. Carvajal 41 (Holotype: QCA [barcode- 252205]; isotype: QCA [barcode- 254675]) .

Description.

Shrubs with short caulescent leaves forming cushions with subterranean woody stems with several ramifications. Leaves palmati-lobed; leaf blade 5.7–7.7 × 6.5–12.8 mm, trilobate with three subdivisions in each lobe; adaxial surface densely covered by stellate trichomes with rays 0.1–0.2 mm long; abaxial surface sparsely covered by stellate trichomes with rays 0.1–0.3 mm long. Stipules adnate to the petioles, forming a protective sheath, 4–7.1 × 2–3 mm, with stellate trichomes on both sides and along the margin, rays 0.3–0.7 mm long; free part of the stipule narrowly triangular, 2–4.5 × 1 mm, with stellate trichomes, rays 0.2–0.6 mm long, on both sides of the stipule. Free part of the petioles 4.5–7 × 0.6–1.2 mm, pubescent on both sides, with stellate trichomes, rays 0.1–0.4 mm long. Flowers 14–18 × 9–12 mm. Calyx 7.5–9.6 × 5.4–8.8 mm; sepals 5, connate, free at the apex forming triangular teeth, 3.1–4.8 × 2.1–3.1 mm, upper surface densely covered by stellate trichomes with rays 0.2–0.5 mm long, lower surface covered only at the apex, forming a triangle of interspersed stellate and bifid trichomes, rays 0.6–1.1 mm long; nectaries 5, transversely elliptic, distributed at the basal part of each sepal, 0.7–1 × 0.5–1 mm. Corolla slightly campanulate, violet with some degradation to white at the basal part of the petals, corolla tube 1–2 × 2–2.5 mm; petals 5, obovate, slightly emarginate, free part of the petals 11–13.6 × 5.5–7.28 mm, densely covered at the base by stellate, villous, and bifid trichomes, rays 0.6–1 mm long. Staminal tube 6–8 × 0.5–0.7 mm, covered with stellate and bifid trichomes, rays 0.5–1.5 mm long; anthers forming a spherical globose head 2–3 × 2–3 mm, covering 1 / 3 of the staminal tube length. Carpels with 11 styles, stigmas capitate. Fruit a schizocarp with 11 mericarps; each mericarp 5.5 × 2.5 mm, densely covered by stellate trichomes with rays ca. 1 mm long. Seeds kidney-shaped, 2 × 2 mm, one seed per mericarp.

Additional specimens examined.

Ecuador • Napo: Antisana, western side of the volcano, cushion bog [sic] inside the Antisanilla crater , 00°28'18"S, 78°11'32"W, 4300 m elev., 22 Nov 2018, P. Sklenář et al. 15876 ( QCA) ; • Alrededores de la Laguna de Santa Lucía, arenal en la cara norte del pico Antisanilla , 00°28.436'S, 78°11.407'W, 4325 m elev., 18 Jan 2025 (fl), E. J. Trujillo et al. 40 ( QCA) ; • Ibid., 00°28.447'S, 78°11.404'W, 4380 m elev., 18 Jan 2025 (fl), E. J. Trujillo et al. 43 ( QCA) ; • Ibid., 00°28.400'S, 78°11.425'W, 4352 m elev., 18 Jan 2025 (fl), E. J. Trujillo et al. 44 ( QCA) ; • Ibid., E. J. Trujillo et al. 45 ( QCA) ; • Ibid., 00°28.388'S, 78°11.420'W, 4352 m elev., 18 Jan 2025, E. J. Trujillo et al. 46 ( QCA) ; • Ibid., E. J. Trujillo et al. 47 ( QCA) ; • Ibid., E. J. Trujillo et al. 48 ( QCA) ; • Ibid., E. J. Trujillo et al. 49 ( QCA) ; • Ibid., E. J. Trujillo et al. 50 ( QCA) .

Distribution, habitat, and ecology.

Nototriche antisanensis is only known from the type locality on the Antisana volcano in the northeastern Andes of Ecuador (Fig. 4 ). It grows in arid and sandy soils behind a peak that protects individual plants from strong winds and freezing. Characteristic taxa growing nearby include Astragalus geminiflorus Bonpl. ( Fabaceae ), Lasiocephalus ovatus Schltdl. ( Asteraceae ), and species of Calamagrostis Adans. and Festuca L. ( Poaceae ).

Phenology.

Recorded flowering in October, November, and January. Fruiting in November.

Etymology.

The specific epithet honors the páramos of the Antisana volcano, where this species was found and collected for the first time.

Preliminary assessment of conservation status.

Nototriche antisanensis is only known from several individuals (<50 mature individuals) growing around the type locality at Antisanilla Peak, in the páramos of the Antisana National Park. Its distribution appears to be restricted to this area due to specific ecological characteristics. Extensive sampling across other páramos yielded no additional records of this species in similarly arid environments. Furthermore, several threats have been identified, including the expansion of the agricultural frontier, climate change, and the construction of infrastructure related to renewable energy projects in nearby cities. Based on the available information and following the IUCN Red List Criteria and Guidelines (IUCN 2024), N. antisanensis is preliminarily assessed as Critically Endangered (CR).

Discussion.

The taxonomy of Nototriche is challenging due to the lack of comprehensive studies and the phenotypic plasticity exhibited by its species in response to extreme environmental conditions. Despite these difficulties, Hill (1906, 1909, 1928, 1932, 1933) and Krapovickas (1950, 1951, 1953, 1957, 1973) provided most of the species descriptions and established key diagnostic characteristics that facilitate differentiation. Among these are the presence and size of the corolla tube, the distribution and morphology of the indumentum, and leaf morphology. Fruit characters and stamen morphology are particularly relevant for distinguishing taxa.

Nototriche antisanensis shares common characteristics with other species of the genus, such as palmati-lobed leaves with multiple subdivisions arranged in a rosette, axillary flowers, stipules adnate to the petiole, nectaries at the base of the sepals, and a dense presence of trichomes on the corolla. Due to certain morphological traits (see diagnosis above) and some ecological features (such as growing in sandy soils), this species was initially misidentified as N. jamesonii in a herbarium voucher at QCA. However, it is clear that N. jamesonii is restricted to the western arid páramos of the Chimborazo volcano and exhibits several morphological differences, as outlined in the diagnosis of N. antisanensis . Additionally, this new species is distinct from other Nototriche species based on several key characteristics (Table 1 ), such as the corolla tube and vagina indumentum.

The corolla tube is a crucial diagnostic feature of the genus ( Hill 1909) and serves as the first-step characteristic for distinguishing these five species. Nototriche phyllanthos and N. hartwegii are the only two species in which this structure is absent (they possess free petals), differing from each other by indumentum length and presence. Nototriche phyllanthos has a glabrous abaxial leaf surface, whereas N. hartwegii has abundant stellate trichomes on both surfaces of the leaf blade. Additionally, N. phyllanthos possesses slightly triangular stipules with a glabrous abaxial surface, while N. hartwegii has oblanceolate stipules that are densely pubescent on both sides.

The other three species, Nototriche antisanensis , N. jamesonii , and N. ecuadoriensis , have connate petals forming a corolla tube and require additional characteristics for proper identification. Nototriche ecuadoriensis is the easiest to distinguish due to its glabrous leaf blades, except for the tips of the lobes, which are villous. In contrast, as specified in the diagnosis, N. antisanensis and N. jamesonii share similar indumentum distribution, type, and size but differ in growth habit (cushion vs. prostrate shrub), rosette morphology (compact vs. lax), corolla tube length (1–2 mm vs. 2.5–4 mm), and fruit composition (11 mericarps vs. 10 mericarps).

Figures

Figure 1. Nototriche antisanensis, from the collection E. J Trujillo et al. 41. A. Habit; B. Leaves in rosette; C. Top view of a flower; D. Fruit. Photographs by Erick Troncoso-López.

Figure 2. Nototriche antisanensis E. J. Trujillo, Muriel, Espinel-Ortiz & Romol. Holotype specimen (E. J. Trujillo et al. 41, QCA [barcode- 252205]).

Figure 3. Nototriche antisanensis E. J. Trujillo, Muriel, Espinel-Ortiz & Romol. A. Habit; B. Leaf; C. Lower surface (left) and upper surface (right) of the sepals; D. Fruit; E. Corolla; F. Isolated mericarp. (A – C, E. Based on E. J. Trujillo et al. 41 (QCA); D, F. Based on E. J. Trujillo et al. 50 (QCA )). Illustrations by Carla J. Rodríguez.

Figure 4. Distribution of Nototriche species in the Andes of Ecuador.