Eryngium pugae I. García, J. Martínez-Ramírez & Ocampo, 2020

García-Ruiz, Ignacio, Martínez-Ramírez, Julio & Ocampo, Gilberto, 2020, A new species of Eryngium (Apiaceae) from the central-western region of Mexico, Phytotaxa 446 (4), pp. 253-259 : 254-257

Eryngium pugae I. García, J. Martínez-Ramírez & Ocampo , sp. nov. ( Figs. 1 , 2A–D )

Type:— MEXICO. Jalisco, municipio de Villa Hidalgo, 4.5 km en línea recta al sur de la presa Los Alamitos, sobre el camino a Villa Hidalgo, bosque de encino, orilla de arroyo, 21.69168°N, 102.70421°W, 2250 m, 22 Aug 2017, J. Martínez-Ramírez et al. 3201 (Holotype HUAA!; isotypes CIMI!, IBUG!, IEB!, MEXU!) .

Diagnosis:— Perennial plant, herbaceous; stems erect, solitary, fistulose; basal leaves few, linear to linear-lanceolate, 0.2–0.5 cm wide, leaf blade fistulose, septate, entire, spines absent, the venation parallel; inflorescences cymosely branched, axillary and terminal, 3–7 heads; heads grey-bluish, ovoid-oblong; involucral bracts linear-lanceolate, equal in size or longer than the head, entire, silvery on the adaxial side; coma absent; globular-ovoid fruit with spherical vesicles.

Perennial plant, herbaceous, (15–) 30–45 cm tall, with fasciculated roots. Stems erect, solitary, fistulose, with sympodial branching. Basal leaves 2–4, sessile, linear to linear-lanceolate, 14–30 × 0.2–0.5 cm, sheath 2–4 cm long, up to 1 cm wide at its base, leaf fistulose, septate, entire, spines absent, apex rounded, the venation parallel; cauline leaves few, similar to the basal leaves but shorter. Inflorescences cymosely branched, 2.5–5.5 cm long, axillar and terminal, with 3–7 heads; heads whitish to grey-bluish, ovoid-oblong, 0.5–1.2 × 0.3–0.6(–0.7) cm; involucral bracts 6–8(–9), extended to ascending, linear-lanceolate, 4–16 × 0.5–2 mm, equal or longer in size than the head, entire, apex rounded, silvery on the adaxial side, light green on the adaxial side; bractlets lanceolate, 1.5 mm long, equal or slightly longer in size than the fruit, entire; coma absent. Flowers white to grey-bluish; sepals oblong-ovate, 0.6–0.7 mm long, obtuse, apiculate, apex with bluish tones; petals oblanceolate, 0.5 mm long, slightly longer than the sepals (in flower), apex bilobate and rounded; filaments 0.3–0.4 mm long, anthers bithecal, basifix, 0.1 mm long; styles divaricate, 0.2–0.3 mm long, longer than the sepals. Fruits globular-ovoid, 1.5–2 × 2 mm, covered with spherical vesicles; seeds 2, 0.9–1.3 × 1.4 mm, flattened on the ventral side, minutely papillose on the dorsal side, yellowish when immature.

Etymology:— The epithet of the species honors the late Luz María Villarreal de Puga, a prolific botanist and professor, who first collected this new species and intensively promoted the knowledge of the flora of the Mexican state of Jalisco.

Distribution and habitat:— As far as we know, there are only two collections of Eryngium pugae . The species has been collected in the Mexican state of Jalisco ( Fig. 3 ), in the areas locally known as “Sierra del Laurel” and “Sierra de Bolaños”, in wet places with oak and oak-pine forests at an elevation of 2250–2450 m. More collection efforts are needed to know the actual distribution of E. pugae , although it is likely to occur in neighboring states with similar habitat conditions (Aguascalientes, Nayarit, and Zacatecas).

Conservation status:— According to the available data, Eryngium pugae occurs in wet places (especially sensitive to habitat disturbance) and is only known from two places that are located in an area less than 5,000 km 2. Therefore, E. pugae should be assessed as Endangered (EN), according to criterion B1ab(iii) ( IUCN 2019).

Paratype:— MEXICO. Jalisco, municipio de Bolaños, Sierra de Bolaños, ceja de la barranca, cerca de albergue, bosque de Quercus y Pinus , 2450 m, 1 Sep 1968, L.M. Villarreal de Puga 1946 (IBUG!).

Discussion:— The new taxon can be placed in Eryngium section Madrensia Wolff (1913: 178) , mainly because of the presence of septate leaves, involucral bracts silvery on the adaxial side subtending bluish to purplish ovoid-globose to ovoid-cylindrical heads ( Wolff 1913; Constance & Bye 1974). Up to now, the section only included three Mexican species which show the same preference for wet habitats within template forests: E. gentryi Constance & Bye (1976: 235) , E. madrense S. Watson (1888: 274) , and E. mexicanum S. Watson (1891: 136) ( Wolff 1913; Constance & Bye 1974).

Within section Madrensia , the new species seems to be morphologically more closely related to E. gentryi by its linear-lanceolate leaves with parallel venation, the absence of a coma, and length of the fruit. However, E. pugae differs from E. gentryi by the entire margin of its basal leaves, higher number of heads, globular-ovoid capitula, fewer involucral bracts, smaller sepals and petals, fruits with spherical vesicles, and known distribution ( E. gentryi is only found in the Mexican state of Chihuahua) ( Table 1); voucher information of examined specimens of E. gentryi are mentioned below. On the other hand, E. madrense and E. mexicanum can be segregated from E. pugae by their entire to pinnatisect leaves with reticulate venation and heads with coma ( Constance & Bye 1974; García-Ruiz 2013).

Additional material reviewed online:— Eryngium gentryi Constance & Bye : MEXICO. Chihuahua, municipality of Bocoyna, E of Gonogochi (on continental divide), E of creel, associated with low, scrubby Quercus , grasses, Ranunculus spp. , Cacalia sp. , and Tagetes lucida , 7900 ft (2370 m), 24Aug 1973, R. Bye 4766 (MEXU!250634, https://datosabiertos.unam.mx/IBUNAM:MEXU:T250634); San Juanito, ca. 5.2 road km of…, margin of open pine forest between railroad tracks and dirt road, 2 depressions of headwater of arroyo with standing water, 28°0’7.07”N, 107°34’52.49”W, 2411 m, unknown date, R. Bye 37568 (MEXU! 1366500, https://datosabiertos.unam.mx/IBUNAM: MEXU:1366500); ejido de San Ignacio Arareco, llano in pine-oak forest N of church, in moist area with standing water, 2200 m, 8 Aug 1977, R. Bye 7883 (COLO! 1153204, http://www.herbanwmex.net/portal/collections/individual/ index.php?occid=13944016; MEXU! 269915, https://datosabiertos.unam.mx/IBUNAM:MEXU:269915); ejido de San Ignacio, llano in pine-oak forest along creel airstrip, without elevation data, 14 Aug 1977, R. Bye 8006 (COLO! 1153220, http://www.herbanwmex.net/portal/collections/individual/index.php?occid=13944018); municipality of Guachochic, mesa de Aboriachic E of Cusarare, ca. km 19 on Cusarare-Choguita road, pine-oak forest, elev. 2250 m, 9 Aug 1977, R.A. Bye 7898 (COLO! 1153212, http://www.herbanwmex.net/portal/collections/individual/index. php?occid=13944017). Chihuahua, municipality of Ocampo, Memelichi, Rio Mayo, transition, pines, meadow, elev. 7500 ft (2286 m), 17 Sep 1936, H.S. Gentry 2270 (ARIZ! 20589, http://www.herbanwmex.net/portal/collections/ individual/index.php?occid=878454).

Figures

FIGURE 1. Holotype of Eryngium pugae (HUAA).

FIGURE 2. Eryngium pugae, A) Section of a specimen showing roots, young basal leaves, and a sheath of a mature basal leaf. B) Longitudinal section of a basal leaf showing a septum. C) Sheath of a cauline leaf. D) Head. E) Fruit. F) Seed.

FIGURE 3. Known distribution of Eryngium pugae.