Quercus salicifolia Née, Anales Ci. Nat.

Valencia-A, Susana & Soto-Arellano, Oscar Javier, 2025, Notes on Quercus salicifolia and description of a new species of Quercus section Lobatae (Fagaceae) from Mexico, Phytotaxa 681 (1), pp. 55-69 : 57-62

Quercus salicifolia Née, Anales Ci. Nat. 3: 265. 1801. Type:— MEXICO, Guerrero, Acapulco, Née 25957 (lectotype

(designated by Muller & McVaugh 1972: 520): MA25957!) ( Fig. 1 ).

= Q. tahuasalana Trelease, Mem. Natl. Acad. Sci. 20: 154, pl. 302b. 1924. Type:— México. Michoacán. El Tahuasal, Langlassé 217 (lectotype (designated by Bartholomew & Almeda 2023: 56): G00358146!).

= Q. acapulcensis Trelease, Mem. Natl. Acad. Sci. 20: 153, pl. 302a. 1924. Type:— México. Guerrero.Acapulco, E. Palmer 334 (holotype GH00069901!).

Common name:—encino saucillo, encino amarillo.

Amended description:—Trees 12‒25 m tall; stems 0.4‒0.6 m diam., twigs 1.3‒2.5 mm diam., terete to slightly furrowed, reddish brown to dark brown, lenticels inconspicuous, glabrous to glabrate with few loosely and heterogeneously distributed stellate trichomes; buds ovoid, ca. 5 mm long, scales glossy, broadly ovate to very broadly ovate, margin moderately ciliate; stipules deciduous. Mature leaves with petioles 2.8‒7.7(‒9.6) × 1.2‒2.4 mm, glabrous, petioles reddish, this color extending to the base of the midvein, frequently brown basally or sometimes entirely brown; blades coriaceous, oblanceolate, narrowly elliptical to lanceolate, 10.5‒20(‒23) × 2.5‒4(‒5.6) cm, 3.7‒4.9 times longer than wider; apex acute to acuminate, tip aristate; margin usually entire, cartilaginous, slightly crispate, rarely crenate or with 1‒2 short aristate teeth towards the apex; base rounded to cuneate, sometimes narrowly oblique; secondary veins 12‒17(‒22) on each side of the midvein, moderately curved, ascending, branching and anastomosing near the margin, with evanescent intermediates, adaxial blade surface slightly dull, glaucous to grayish green, secondary veins and veinlets yellowish, the midvein slightly reddish-brown basally, slightly raised to smooth; abaxial blade surface slightly shiny, yellowish‒green, glabrous or with tufts of fasciculate shortly stipitate to sessile trichomes in the axils of the secondary veins, secondary veins slightly raised and yellowish, epidermis slightly papillose or smooth. Fruits annual, 1‒2 sessile on the twigs of the current season, cupules obconical, incipiently turbinate, 10.5‒11.5 mm diam. × 6.3‒8.1 mm tall, margin erect, scales triangular, canescent and smooth, yellowish-beige; acorns ovoid, yellowishbrown, 8.5‒9.7 mm diam. × 13.5‒14.6 mm tall, covered with a fine canescent indumentum, included 1/4‒1/3 of their total length in the cupule ( Figs. 2A‒2E ).

Distribution and ecology:— Mexico (Chiapas, Guerrero, Jalisco, Michoacán, and Oaxaca), probably in Guatemala. On the Pacific slope of the Sierra Madre del Sur. Elevation 115‒1250 m. Occurs in pine-oak forest, tropical subdeciduous forest and oak forest. Associated with Q. planipocula Trelease (1924: 136) , Q. magnoliifolia Née (1801: 268) and Q. peduncularis Née (1801: 270) . Flowering in November, fruits mature from June to August.

Conservation status:—It was assessed by Carrero et al. (2020) as Vulnerable (VU).

Additional specimens examined:— MEXICO, CHIAPAS. Municipality Villa Corzo: Rancho Lindavista, 15º58’36”N, 93º18’00”W, 19 May 1998, M. V. Velasquez 314‒317 ( MEXU). GUERRERO. Municipality Acapulco: Parque Nacional El Veladero, 650 m, 23 March 1985, N. Noriega 503, ( FCME). Municipality Apango: La Encinera, 535 m, 17º36’34.4”N, 101º05’15.5”W, 15 November 2013, E. Hernández N-12 ( FCME). Municipality José Azueta: La Mesa de Bravo , brecha carr. Zihuatanejo-Vallecitos de Zaragoza a La Iguana , 28 March 2008, R. Díaz 26 ( INEGI) ; Ejido Barranca de la Bandera, 596 m, 17º46’39”N, 101º27’49.3”W, M. Hernández 601 ( FCME). Municipality Petatlán: Los Llanos, 495 m, 17º39’41.5”N, 101º17’12.2”W, 29 July 2012, A. Almazán 1980 ( FCME) ; entre Las Mesas de Los Bravo y Rabo de Iguana, 30 November 1973, F. González 6580 ( MEXU). Municipality Técpan de Galeana: El Rincón, El Chivo, J. C. Calvillo 12-02415-01 ( FCME) ; predio El Cuellado. Paraje El Aguacatoso, J. L. Flores JLF540 ( MEXU) ; El Porvenir, 1000 m, 27 June 2002, R. Mayorga 2008 ( FCME) ; 3 km al NE de El Porvenir, 820 m, 7 February 1986, J. C. Soto 12340 ( MEXU). Municipality La Unión: Vallecitos, Montes de Oca , 550 m, 25 November 1936, Hinton et al. 9901 ( CHRB, MEXU), 10292 ( CHRB). JALISCO. Municipality Casimiro Castillo : Km 9 brecha Tecomates-Cuautitlán , 23 January 1983, L. M. González 1648 ( MEXU) ; brecha Tecomates-Cuautitlán, A. Ramos et al. 4 ( MEXU). Municipality Manantlán: ca. 40 km south-east of Autlán, 2‒3 km above the abandoned site of Durazno, along the lumber road between El Chante and Cuzalapa, 1250 m, 19º32’N, 104º14’W, 24 March 1965, R. McVaugh 23251 ( MEXU) ; Km 47 Tomatlán-P. Vallarta, 16 December 1970, A. Pérez 451 ( MEXU) ; Las Palmillas, Villa Purificación, 1120 m, 19º54’39.4”N, 104º35’39.8”W, 3 June 2010, DIAAPROY S. A. de C. V.s.n. ( MEXU) ; Cerro el Remunadero, Villa Purificación, 1280 m, 19º51’10.6”N, 104º38’25.8”W, 2 June 2010, DIAAPROY S. A. de C. V.s.n. ( MEXU) ; San Miguel de las Ventas, San Sebastian del Oeste , 1112 m, 20º45’17”N, 104º53’57.9”W, 23 June 2010, DIAAPROY S. A. de C. V. s.n. ( MEXU) ; El Zopilote, Talpa de Allende , 9 June 2010, DIAAPROY S. A. de C. V. s.n. ( MEXU) ; 5 km al N de La Cuesta, camino a Talpa, 18 November 1960, Rzedowski 15076 ( MEXU) ; 39 km al W de San Sebastián, 600 m, 29 December 1981, L. M. González 1273 ( MEXU). Municipality San Sebastián: 46 km al NW de Mascota, 1280 m, 28 December 1981, L. M. González 1201 ( MEXU). MICHOACÁN. Municipality Arteaga: km 306 along Hwy. Playa Azul-Arteaga (MX-37) ; 2 km S of Buenavista II, 615 m, 18º12’16.2”N, 102º15’40”W, 1 March 2007, R. McCauley 428 ( MEXU) ; About 25 km south of Arteaga, road to Playa Azul, 600‒650 m, 27 February 1965, R. McVaugh 22642 ( MEXU). Municipality Coalcomán : Sierra Naranjillo , B. Hinton 13748 ( CHRB). OAXACA. Municipality Santa María Ecatepec : Teipan , 26 July 2002 C. Ruíz s.n. ( FCME) .

Notes:— Quercus mexicana var. glabrata Liebmann ex Seeman (1856: 332) and Q. castanea var. glabrata (Liebmann ex Seeman) A. de Candolle (1864: 72) were proposed by Valencia-A. and Coombes (2020) as synonyms of Q. salicifolia Née. After an examination of the characters that define the latter, and by critically comparing the types and the protologues of both taxa, we can see that the Seemann 1974 collection (on which the names Q. mexicana var. glabrata and Q. castanea var. glabrata were based) are not conspecific with Q. salicifolia , but with Q. confertifolia Bonpland (1809: 53) . Therefore, the proposal of Bartholomew & Almeda (2023), that considers Q. mexicana var. glabrata and Q. castanea var. glabrata as synonyms of Q. confertifolia , is supported here.

Quercus salicifolia has been frequently confused with other species of Quercus section Lobatae ( Loudon 1830: 385) from Central America and southern Mexico, since many of these have more or less lanceolate or narrowly elliptical to lanceolate blades, glabrous, and entire margins which led to treating them as synonyms of Q. salicifolia ( Stevens et al. 2001; Linares 2003; Correa et al. 2004; Morales 2010; Bartholomew and Almeda 2023). However, there are other characteristics such as color and consistency of blades, the shape of the base and apex, the direction and number of secondary veins, as well as the shape and size of the acorn and cup, which allow us to distinguish each entity and consider them as different species. The names of the species that have been proposed as synonyms of Q. salicifolia and the characters that support the proposal presented here for each case are listed below.

Quercus boquetensis Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 22(1): 13. 1940.

Type:— PANAMA, Chiriquí, M. E. Davidson 780 (holotype F 935137!, isotypes US 00089445!, GH 00055560!).

This differs from Q. salicifolia by a combination of its linear-lanceolate leaves, acute to acute-acuminate at the base and apex, inconspicuous secondary veins, and dark-brown and glabrate twigs.

Flora Mesoamericana (Tropicos.org/Project) proposes Q. boquetensis as a synonym of Q. cortesii Liebmann (1854: 175) , but this is incorrect given that the type specimens of Q. boquetensis ( F 935137, US 00089445, and GH 00055560) show a greater number of characters in common with Q. seemannii , with which it could be conspecific. However, additional studies are required to clarify this identity.

Known distribution:— Panamá ( Fig. 2F ).

Quercus citrifolia Liebmann, Overs. Kongel. Danske Vidensk. Selsk. Forh. Medlemmenrs Arbeider 187. 1854.

Type:— COSTA RICA. Cartago, A. S. Oersted 3461 (lectotype (designated by Bartholomew & Almeda 2023: 55) C 10012469!) ( Fig. 2H ).

= Q. borucasana Trelease, Mem. Natl. Acad. Sci. 20: 161. Pl. 315a. 1924.

Type:— COSTA RICA, Cartago, A. S. Oersted 3491 (holotype: C 10014102!). = Q. granulata Liebmann , non Rafinesque (1838: 21). Overs. Kongel. Danske Vidensk. Selsk. Forh. Medlemmenrs Arbeider 186: 1854 ( Fig. 2G ).

Quercus citrifolia Liebmann and Q. borucasana Trelease are variations of the same taxon. Considering the principle of priority of the International Code of Nomenclature for algae, fungi and plants ( Turland et al. 2018), Q. citrifolia is the name that must be applied to this species and Q. borucasana is its synonym. Quercus citrifolia is distinguished from Q. salicifolia by its shorter, broadly elliptic to oblong, coriaceous leaves, leaf base truncated, obtuse to rounded, veins in smaller number, slightly impressed above, and diverging at an almost perpendicular course to the middle vein, leaf margin revolute, petioles slightly winged, buds ovoid, and its twigs dark brown with conspicuous lenticels. Burger (1977), Muller (1942), and Flora Mesoamericana (Tropicos.org/Project) list it as a synonym of Q. seemannii Liebmann , which can not be maintained here, because Q. seemannii has subcoriaceous and lanceolate leaf blades, and its petioles are longer. Additionally, Q. citrifolia is found on the ridge of mountains, while Q. seemannii grows in areas more protected from the sun and wind, even in cloud forest.

Known distribution:— Costa Rica, Guatemala and Panamá. It is possible that it could also be present in Honduras and Nicaragua.

Quercus eugeniifolia Liebmann, Overs. Kongel. Danske Vidensk. Selsk. Forh. Medlemmenrs Arbeider : 185. 1854. Type:— COSTA RICA, J.R.R. Warszewicz s.n. (lectotype (designated by Bartholomew & Almeda 2023: 55): image in Trelease 1924, pl.

316a) ( Fig. 2I ).

Bartholomew & Almeda (2023) point out that the image of Trelease corresponds to Q. salicifolia . While Q. eugeniifolia is similar to Q. salicifolia in having elliptical leaves with a cuneate to acute base and an acute to acuminate apex, it differs in the revolute margin, the secondary veins diverging almost at a right angle to the midvein and being impressed on the adaxial surface, and the twigs having conspicuous lenticels. Although Burger (1977) proposed it as a synonym of Q. seemannii , we consider that there is still a lack of information in this regard, so in the meantime, we maintain both as different species.

Known distribution:— Costa Rica.

Quercus mulleri Martínez, Anales Inst. Biol. Univ. Nac. Autón. Méixco 24(2): 51, fig. 1, 2. 1953.

Type:— MEXICO. Oaxaca.Inter San Pedro Sosoltepec et Tacubaya, Distrito de Yautepec, T. MacDougall 2435 (holotype MEXU00011238!) ( Fig. 2J ).

This species differs from Q. salicifolia in its narrowly lanceolate, long acuminate, and coriaceous leaves, which additionally have an olive-green colour, a slightly revolute margin, secondary veins diverging at an almost right angle from the midvein and they are concolorous, with a rounded base. So, we recognize this as a different taxon and its synonymy is not accepted here. Known distribution:—microendemic of Mexico, in Oaxaca and possibly Chiapas.

Quercus nixoniana S. Valencia & Lozada-Pérez, Novon 13(2): 261. 2003.

Type:— MEXICO. Guerrero. R. De Santiago 747 (holotype FCME!) ( Fig. 2K ).

The greater number of veins and longer leaves, as well as other characters shown in Table 1, distinguish Q. nixoniana from Q. salicifolia .

Known distribution:— Mexico, in Guerrero, Jalisco, and Oaxaca.

Quercus obtusanthera Trel., Repert. Spec. Nov. Regni Veg. 33: 318. 1934.

Type:— MEXICO. Guerrero. Sierra Madre del Sur, Höhen im NE von Malinaltepec, March 1930, L. Schultze 343 (holotype B, destroyed).

The description states that the twigs are grayish, with ellipsoid lenticels, and ellipsoid buds, as well as deciduous, lanceolate, and acute (at both ends) leaves. It was collected at 2000 m of elevation. With the exception of the bases that could be cuneate in Q. salicifolia , the rest of the characteristics indicated above do not coincide with the characteristics of Q. salicifolia , since it has reddish to brown twigs, and inconspicuous lenticels. Additionally, the elevation and location of collection of Q. obtusanthera are different from those of Q. salicifolia , which does not exceed 1300 m asl, and is found mainly on the Pacific slope of the Sierra Madre del Sur, so this synonymy is not accepted here for Q. salicifolia .

Known distribution:—data deficient, only known from the protologue.

Quercus rubramenta Trel., Repert. Spec. Nov. Regni Veg. 33: 318. 1934.

Type:— MEXICO. Guerrero. Sierra Madre del Sur, Gipfel des Berges Lucerna im NE von Malinaltpec, L. Schultze 371 y 372 (syntypes B, destroyed, neotype (designated here): MEXICO. Guerrero, Municipality Malinaltepec, Al NE de Malinaltepec, cerro de La Lucerna, S. Valencia 487 ( FCME 07399!) ( Figs. 3 and 2L ).

Its broader leaves with finely crisped margin, a greater number of secondary veins that are regularly distributed and almost equidistant from each other, petioles up to 5 cm long and subtly winged, catkins reddish (from which the specific epithet is derived), as well as its larger and biennial fruit readily distinguish Q. rubramenta from Q. salicifolia . Its habitat includes cloud forest, humid oak forest, and humid oak-pine forest, and it reaches 2950 m asl.

Known distribution:—Microendemic of Mexico, in Guerrero and Oaxaca.

Quercus seemannii Liebmann, Overs. Kongel. Danske Vidensk. Selsk. Forh. Medlemmenrs Arbeider : 188. 1854. Type:— PANAMA. Veraguas. B. Seemann 1228 (lectotype (designated by Trelease 1924: 226, pl. 317a) K000575040!). = Q. salicifolia var. seemannii (Liebmann) Wenzig, Jahrb. Königl. Bot. Gart. Berlin 3: 207. 1884 ( Fig. 2M ). = Q. eugeniifolia f. petiolata Trelease, Mem. Natl. Acad. Sci. 20:161, pl. 316b. 1924. Type:— COSTA RICA. C. Hoffmann 863 (lectotype (designated by Bartholomew & Almeda 2023: 56) image in Trelease 1924, pl. 316b).

= Quercus petiolata (Trelease) A.E. Murray not Schur (1857), Kalmia 13: 27. 1983.

This differs from Q. salicifolia in its ovate buds, longer and subtly winged petioles, lanceolate to ovate leaves of subcoriaceous consistency and secondary veins slightly or not impressed on the adaxial surface of the leaves; additionally, these are concolorous with respect to the surface; fruits 1‒4 on a peduncle of ca. 2 cm long, the scales on the cup are wide and light brown.

Known distribution:— Costa Rica, Mexico (Chiapas), and Panama. It is possible that it may also be present in Honduras and Nicaragua.

Figures

FIGURE 1. Fragment of the lectotype of Quercus salicifolia Née (MA). Photo by Susana Valencia-A.

FIGURE 2. Different leaf shapes of Quercus salicifolia Née and the species that have been considered as its synonyms. The majority of shapes were taken from the type specimens. A, B. Q. salicifolia lectotype; C. Q. acapulcensis; D. Q. tahuasalana; E. Q. salicifolia from the specimen N. Noriega 503 (FCME), collected in Acapulco, Guerrero; F. Q. boquetensis; G. Q. borucasana; H. Q. citrifolia; I. Q. eugeniifolia; J. Q. mulleri; K. Q. nixoniana; L. Q. rubramenta; M. Q. seemannii. Drawn by Susana Valencia-A.

FIGURE 3. Neotype of Quercus rubramenta Trel. Photo by Gabriela Flores Valencia.