Santolina razaneae Homrani-Bakali, Chamboul. & Léger, 2025

Bakali, Abdelmonaim Homrani, Chambouleyron, Mathieu & Léger, Jean-François, 2025, Santolina razaneae (Asteraceae), a new steppic species from Morocco, Phytotaxa 693 (3), pp. 235-244 : 236-239

Santolina razaneae Homrani-Bakali, Chamboul. & Léger , sp. nov. ( Figs. 1 , 2 , 4 and 5 )

Diagnosis: — Santolina razaneae differs from the four other species found in the wild in Morocco ( S. africana , S. pectinata , S. ascensionis , and S. canescens ) by its distinctive pinnate leaves with obtuse lobes, unusual florets with pale pinkish lobes, smaller involucres and large, triangular, lacerate, glabrous paleae. The morphologically closest species found in Iberian floras ( Blanca 2011; Carbajal et al. 2019), especially regarding leaf characteristics, are S. viscosa Lagasca (1816: 25) and S. orocarpetana Rivero-Guerra (2012: 152) ( Blanca 2011; Rivero-Guerra 2012; Carbajal et al. 2019):

- S. viscosa differs from S. razaneae by its viscid-glandular pubescence, yellow flowers, and paniculate (vs monocephalous) inflorescence;

- S. orocarpetana differs from S. razaneae by its glaucous sericeous indument (vs grayish sericeous), upper leaves generally bi- or trilobed just along the upper third (vs entire to multilobate), flowers yellow (vs pale pink), and apical appendage scarious-transparent (vs scarious-brown).

Description: —Shrubby chamaephyte 10–40(50) cm tall, rhizomatous, greyish, not glandular. Large stump without caudex. Vegetative stems erect; fertile ones unbranched in their upper part, canescent to tomentose. Leaves 5–20(25) × 1–8(10) mm, nearly flat, sericeous, with subsessile petiole appressed to the stem. Cauline and upper leaves not similar in size and shape; the cauline ones oblanceolate pinnatisect and upper leaves linear-entire, leaflets arranged in 1–5 pairs (2–11 elliptical lobes) of sessile, linear, obtuse leaflets 1–7(8) mm long, sometimes ending in a caducous spinule; the upper ones generally narrowly elliptical, entire. Capitula solitary, 7–13 mm across, homogamous, discoid, hemispherical to subglobose, not thickened and sericeous at the base. Involucre 5–9 mm wide, not umbilicate, sericeous; phyllaries villous, arranged in 2–3 rows, triangular-lanceolate, with a brown eroded scarious apical appendage, with very slightly scarious margins. Receptacle subglobose with paleas 3–4 × 0.8–1 mm, lanceolate, flat to ± concave, scarious, ending in a triangular lacerate subglabrous apex (few hairs), progressively acuminate. Florets 4–5 mm long, hermaphrodite, tubular with triangular pale pinkish lobes and a slightly sacciform yellow tube. Achenes 1.8–2.8(3) × 0.6–0.9 mm, oblong to narrowly obconical, very finely striated, showing 2–3 pseudo-ribs faintly marked on the internal face, brown, shiny, covered with mucilaginous cells over the entire surface. Pappus absent.

Type: — MOROCCO. Boulemane Province , Enjil Ikhatern municipality, Enjil Ait Lahcen village, coordinates ( WGS84 ): 33.193511, −4.588778, elev. 1670 m, 29 May 2024, A. Homrani Bakali (holotype RAB-114777, Fig. 1 ; isotype RAB-114778) .

Paratype: — MOROCCO. Boulemane Province, Enjil Ikhatern municipality, inside the fenced reserve of the Emirate Center for Wildlife Propagation, coordinates: 33.15417, −4.57895, elev. 1610 m, 19 June 2020, M. Chambouleyron ( ECWP s.n.).

Etymology: —The specific epithet was derived from the first name of the first author’s elder daughter, Razane Homrani Bakali.

Distribution and ecology: — Santolina razaneae is currently known in eastern Morocco (upper Moulouya basin, and High plateaus – Op-2 and Op-3 sensu Fennane & Ibn Tattou 2005), at elevations of 1100 to 1700 m a.s.l. Its presence in western Algeria (High plateaus) is highly probable since it has been found near the Algerian border. ( Fig. 3 ). This area receives an annual rainfall of c. 200–600 mm (after Roux et al. 1949), with a high interannual variability (occasional drought years with less than 50 mm of rainfall), corresponding to arid to semi-arid bioclimates (sensu Emberger 1955). Its habitats are mostly steppes (dominated by grasses and/or chamaephytes), but it can also grow along the edges of small wadis and temporary ponds (dayas).

Phenology: —Blooming occurs from late April to June, with occasional re-blooming in autumn if weather conditions are favourable, but with fewer flowers than in the spring.

Conservation: —In eastern Morocco, most steppic habitats are severely degraded due to the combination of heavy overgrazing (mostly by sheep and goats) and recurrent droughts. Fortunately, an important population of S. razaneae is protected within the fenced-off area of the Emirates Center for Wildlife Propagation (ECWP)’s Enjil site.

We strongly encourage the creation of new fenced reserves, nevertheless, given the uncertainty regarding the longterm maintenance of fenced-off areas in livestock-breeding regions, we recommend that a seed collection campaign be initiated. The collected seeds could be preserved at the INRA seed bank (Settat, Morocco).

Previously, all Santolina species were classified as LC (Least Concern) by Fennane (2021). Regarding S. razaneae , due to the lack of data on its potential population size reduction, and/or on its geographic range fluctuation/decline/ fragmentation, and/or on its number of mature individuals decline, we cannot propose any threat category according to the IUCN guidelines ( IUCN 2024). Pending more comprehensive surveys and counts of S. razaneae individuals, we propose to assign it the ‘Data Deficient’ (DD) category. However, considering climate change and aridification in eastern Morocco and Algerian High plateaus (e.g., Thomas & Nigam 2018), in conjunction with their continuous overgrazing, the number of mature individuals is likely declining; if it falls below 1,000 individuals, the species could be proposed for the ‘Near Threatened’ (NT) category.

Figures

FIGURE 1. Holotype specimen of Santolina razaneae (RAB 114777).

FIGURE 2. Santolina razaneae, A. plants in native habitat; B. plant habit; C. leaves with small spinules; D. capitulum with pale pink tubular florets; E. phyllaries with apical ± brown eroded scarious appendage (external); F. oblong achenes. Photo A taken by the second author; photos B–F taken by the first author.

FIGURE 3. Known localities of Santolina razaneae in Morocco.

FIGURE 4. Variability of the leaf shape from the upper (left) to the lower part of fertile stems of the three Santolina species of Morocco: A. S. razaneae; B. S. africana; C. S. pectinata.All photos taken by the first author.

FIGURE 5. Variability of the floret with palea, the palea, and the external phyllary, respectively, in Santolina razaneae (A, B, C), S. africana (D, E, F) and S. pectinata (G, H, I). All photos taken by the first author.