Echeveria marianae I. García & Costea, 2014

García-Ruiz, Ignacio & Costea, Mihai, 2014, Echeveria marianae (Crassulaceae), a new species from Jalisco, México, Phytotaxa 170 (1), pp. 35-40 : 36-38

Echeveria marianae I. García & Costea , sp. nov., Figs. 1–2 .

Type:— MÉXICO. Jalisco: Municipio de Valle de Juárez, Barranca del Ojo de Agua al este de Mazamitla, 2460 m, bosque de encino-pino con elementos de bosque mesófilo de montaña; 29 Augusto 2013, I. García & M. Costea 8732 (holotype CIMI! isotypes; DAO!, ENCB!, IEB!, MEXU!, MICH!) .

Similar morphologically to E. novogaliciana and E. dactylifera in the absent or short caudex, calyx with unequal sepals, and presence of corolla appendages at the base of epipetalous stamens but differing from both species in the general leaf shape, carinate petals, external orange colour, toward the tips darker-orange to reddish, and convergent, ascending or erect corolla appendages. In addition, it differs from E. novogaliciana in the smaller leaf rosettes, inflorescences with fewer cincinni, and shorter stamens, and from E. dactylifera in the shorter pedicels, smaller flowers, and reniform, pink nectaries.

Perennial herb, not cespitose, glabrous, light green to yellow-green, not glaucous, acaulescent or short caulescent, caudex (when present) 4–6 cm long and 3–4 cm in diameter; rosette lax, 30–40 cm in diameter with 16–18 (22) leaves; leaves light-green to yellow-green, obovate to oblanceolate, 5–22 (24) × 3–7.5 cm, thickness of lamina at the base 6–9 mm; entire or sometimes 2–4-lobed distally, base amplexicaulous, apex acute to apiculate, margins with a thin, red line, somewhat crenulate in young leaves; inflorescence paniculiform thyrse, solitary or double, 80–90 (100) cm long and 6–13 cm wide, with (7) 8–10 secondary axes (cincinni), each with 1–6 flowers; bracts of the main inflorescence axis (7) 8–10, oblong to ovate-lanceolate, 2–6.2 × 0.5–1.5 cm, base auriculate, upper ones caducous; bracts of cincinni similar to those on the main axis but 18–22 × 4–6 mm; pedicels 5–9 mm long and 2–3 mm thick; calyx gamosepalous, the tube 2.3–2.5 mm long, lobes unequal, spreading to slightly recurved, triangular-lanceolate, green, 9–15 × 3–6 mm; corolla pentagonal-conical in bud, urceolate to campanulate at anthesis, 15–20 mm long, 10–12 mm in diameter at the base, opening distally for 4–8 mm; petals imbricate, oblong-lanceolate with a concavity at the base corresponding to the nectaries, 15–20 × 6–7 mm, slightly recurved, tips mucronate, external color pale yellow-whitish at the base, orange in the rest with dark-orange to reddish tips, internal color pale, yellow at the base, yellow-orange in the rest, tips reddish; nectaries reniform, 3 × 1 mm, pink with darker margins; epipetalous filaments (including the anthers) 7–9 mm long, with 1 or 2 multicellular corolla appendages at the base (sometimes one is basally bifid giving the impression of 3 appendages present at the base of the stamen), linear, oblanceolate or conical, convergent, ascending or erect, 1–5 × 0.5–1 mm, sometimes with a red line on the margin toward the apex, surface with epicuticular wax organised as parallel rodlets; episepalous filaments (including anthers) 10–12 mm long; anthers 2–2.5 × 1 mm, yellow to red; pollen agglutinated into large masses, tricolpate, oblate in equatorial view, triangular in polar view, 30–32 × 14–16 µm, tectum imperforate, scabrate; ovary with 5 carpels, 10–13 × 4 mm, white-yellowish; styles (including the stigmas) 4–5 mm long, reddish at the base and dark brown-reddish apically; stigma globose; fruit suberect follicles, 8.5 × 2.8 mm; seeds numerous, oblong to obovate, light to dark-brown, reticulate, 0.6–0.8 × 0.25–0.3 mm; reticulum size 40–50 µm.

Discussion: —As indicated in the diagnosis E. marianae shares close morphological affinities with E. novogaliciana and E. dactylifera but differs from both in the morphology of the leaves, carinate corolla lobes which are orange-colored with darker red tips, and a different morphology of the corolla appendages. For a detailed comparison see Table 1. The lobed leaves character can be seen especially in mature plants with larger rosettes; young plants may have all the leaves entire. The plants cultivated in Jiquilpan, Michoacán at a lower elevation (1560 m), under full sun and higher temperature conditions were similar to those in the wild but had smaller flower (14–16 mm long), narrower leaves, the corolla had a more uniform and stronger shade of orange ( Fig. 1L ), sometimes with pink-red areas, and the nectaries were also red. Also in cultivated plants, the calyx was yellow-greenish to orange (not light-green as in the wild plants).

The epidermis of the nectaries in E. marianae has numerous stomata surrounded by epidermal cells filled with anthocyanin pigments, which give the overall pink or red color to the nectaries of this species ( Fig. 1I–K ). The nectar released through the stomata accumulates in the cavities found at the base of the petals, which are covered in part by the coralline appendages found at the base of the epipetalous filaments ( Figs. 1H ; 2A ). Based on the absence of secretory structures ( Fig. 2B–C ), the role of the corolla appendages is likely to shield the nectar from the pollinators lacking a specialized feeding apparatus. Corolla appendages at the base of stamens have also evolved in Pachyphytum ( Walther 1972; Thiede & Eggli 2007), a genus that forms a sister clade to the remaining “ Echeveria group” (Carrillo- Reyes et al. 2009).

Distribution and ecology: — Echeveria marianae is currently known only from Sierra del Tigre, Jalisco at elevations between 2450–2550 m. The species is saxicole or sometimes epiphytic (e.g., on Quercus sp. ) and it grows in shaded habitats that maintain sufficient humidity even during the dry season, for example, in wet ravines or margins of streams. The general type of vegetation consists of mesophyllous oak and pine forest. The flowers are pollinated by hummingbirds.

Phenology: —Flowers from August to October.

Conservation status: — Based on the area of occupancy and the very small population size we assess E. marianae as Vulnerable (VU) ( IUCN 2001) based on criteria D. Although an exhaustive survey has not been undertaken the species is known from a single locality of less than 10 km 2 (criterion B.2 and condition B(a)) with less than 100 plants among which less than 50 are mature and the Sierra del Tigre is not a protected area and the nearby touristic resort of Mazamitla continues to expand through new constructions in the region.

Etymology:— The specific epithet is dedicated to Mariana the youngest daughter of the first author in recognition of her dedication and care for cultivated material of this species.

Additional specimens examined:— MÉXICO. Jalisco: Municipio de Valle de Juárez , Peñas del lado sureste de El Tigre, 2550 m, 22 September 1997, I . García 4975 ( CIMI!); Municipio de Valle de Juárez, Peñas del lado sureste de El Tigre, 2550 m, 10 October 1998, I . García 5520 ( CIMI!). Both specimens resulted from plants cultivated in Jiquilpan , Michoacán after transplantation from the type locality .

Figures

FIGURE 1. Echeveria marianae. A–K. Type specimen(s) prior to conservation. L–M. Flower(s) from transplanted plant. A. Habit and habitat. B. Inflorescence. C. Bract of secondary inflorescence axis (cincinnus). D. Leaf rosette. E. Lobed leaf. F. Flower (lateral view). G. Flower (distal view). H. Opened flower. I. Base of ovary with nectaries (scale bar = 1 mm). J. Dissected nectaries (scale bar = 0.5 mm). K. Stomata on epidermis of nectaries (scale bar = 100 µm). L. Flowers. M. Dissected flower.

FIGURE 2. Micromorphological features of Echeveria marianae (from holotype material fixed in FAA prior to pressing/drying). A–C. Corolla appendages at the base of the epipetalous stamens. A. General morphology. B. Surface of corolla appendage (note the lack of stomata and presence of epicuticular waxes). C. Distal part of appendage without secretory structures. D. Pollen grain. E–F. Seed morphology. E. General view of seed. F. Surface of seed coat reticulum. Scale bars and SEM data are embedded in the images.