Salvia dugesiana Epling (1939: 343)

González-Gallegos, Jesús Guadalupe & Bedolla-García, Brenda Y., 2023, Rediscovery of Salvia dugesiana (Lamiaceae) in Guanajuato, Mexico, after 129 years, Phytotaxa 629 (1), pp. 1-12 : 3-7

Salvia dugesiana Epling (1939: 343)

Type:— MEXICO. Guanajuato. Montagnes pierreuses, 1894, A. Dugès 226 (lectotype GH (barcode 00001614); here designated) .

Perennial herb to subshrub, 0.6–1.5 m tall; stem densely pilose and covered with light amber glandular dots, also with some glandular-capitate hairs along young branches. Leaves with petiole (1.4–) 2.5–5 cm long, pubescent as the stems; leaf blade ovate to ovate-lanceolate, (4.4–)8–14 × (2.1–) 4–8.3 cm, apex acute, base short cuneate to oblique, margin crenate to serrate, sparsely pilose above, moderately pilose beneath with the hairs mainly along the veins, and with translucent amber glandular dots. Inflorescence in racemes 7.8–17(–27) cm long, with 3–8(–10) floral nodes, each one (4–)6–12(–18)-flowered, the lowermost 2.2–2.7 cm apart from each other; flora axis densely covered with pilose and glandular-capitate hairs, puberulent and with light amber glandular dots. Floral bracts deciduous, usually red, ovate to ovate-lanceolate, 3.7–10 × 1.7–6 mm, apex caudate, base truncate, margin entire, outer surface pilose and covered with light amber glandular dots; occasionally the lowermost floral bracts seem to be reduced leaves, reaching 13–22 × (6.2–) 9–12 mm, and with serrate margin in the lower half portion. Flowers with pedicel 6.2–10 mm long, hirtellous with glandular-capitate hairs. Calyx red, hirtellous with glandular-capitate hairs and covered with amber glandular dots, internally short hispidulous with antrorse hairs, 10–16 × 3.8–5.2(–7) mm, lips acuminate and then long caudate, upper one 7-veined and entire. Corolla red, short pilose and with some tiny glandular-capitate hairs in the lips, tube 20–26 × 6.3–8.7 mm, slightly ventricose, not invaginated near the base and internally epapillate; upper lip 7–10.3 mm long; lower lip 6–11 × 5–8 mm, incurve-concave. Stamens included; filament 3–5 mm long; connective 17–22 mm long, ornated with a ventral cleft with short acute teeth at its extremes; theca 3.2–3.5 mm long; staminodes filiform, 0.9–1 mm long, placed above and behind filament insertion in corolla basal third. Gynobasic horn 1.3–2.6 mm long; style 24–36(–40) mm long, scarcely short pilose, upper stigmatic branch arcuate and longer, the lower one acute at the apex. Immature mericarp ovoid, 3–4 × 1.8–2 mm, mature ones not seen.

Phenology:— The plant was found in full bloom in mid-August and with immature fruits, so it is very probable that blooming extends from late June to at least late November; and fruits should be maturing from late August to November as well.

Distribution, habitat and ecology:— Salvia dugesiana is known exclusively from the locality near Cueva de Santa Regina in Huanímaro, southwestern Guanajuato, very close to the boundaries with Michoacan state ( Fig. 1 ). It inhabits in shady ravines with tropical deciduous forest with the trees Agonandra racemosa ( de Candolle 1825: 41) Standley (1920: 506) and Heliocarpus terebenthinaceus (de Candolle 1813: 114) Hochreutiner (1914: 125) as dominant, and Euphorbia tanquahuete Sessé & Mociño (1894: 122) and Ipomoea murucoides Roemer & Schultes (1819: 248) at the upper edges of the ravine. It shares habitat also with the herbs and shrubs Dioscorea Linnaeus (1753: 1032) sp. , Euphorbia graminea Jacquin (1763: 151) , Jaltomata procumbens ( Cavanilles 1791: 53) Gentry (1973: 287) , Justicia candicans ( Nees 1847: 396) Benson in Benson & Darrow (1981: 218), J. caudata Gray (1886: 405) and Schizocarpum parviflorum Robinson & Greenman (1894: 386) .

Etymology:— The species was name in honor of its first collector, Alfred Dugès. The prolific field work done by Dugès is recognized by a total of 55 species dedicated to him, including fungi, plants, invertebrates, and vertebrates ( Ríos-Muñoz et al. 2018). There are still 10 flowering plants species retaining the epithets dugesii or dugesiana in their accepted names, and the monotypic genus Dugesia Gray (1882: 215) of the Asteraceae .

Additional specimens examined:— MEXICO. Guanajuato. Guanajuato, 1880, A. Dugès s.n. ( GH!) ; mpio. Huanímaro, Cueva de Santa Regina, cañada junto a la vereda de ascenso, 1.7–1.8 km al N de Huanímaro , 20º22.99’N 101º30.22’W, 1830 m, 30 August 2023, J. G. González-Gallegos, B. Y. Bedolla-García, L. Ruacho-González, J. Noriega-Villa, M. H. Sandoval-Ortega & S. Ruiz 2926 ( CIIDIR!, IBUG!, IEB!, MEXU!, XAL!) .

Discussion:— Salvia dugesiana was originally placed in Salvia sect. Secundae ( Bentham 1848: 331) Epling (1939: 342) , a group made up of South American species (except S. dugesiana ). Epling (1939) pointed out that the assignment was provisional until more material with mature corollas could be observed, and indeed, the current examination of floral characters reveals a better match with sect. Holwaya Ramamoorthy (1984: 323), equivalent partially to the Mexican species recognized by Epling as part of sect. Nobiles ( Bentham 1848: 328) Epling (1939: 280). Salvia sect. Holwaya was coined to embrace the Mexican species previously placed in sect. Cardinales Epling (1939: 295) but left out of this when Ramamoorthy (1984) synonymized the type species, S. cardinalis Kunth (1817: 301) , with S. fulgens Cavanilles (1791: 15) , which is the type of sect. Fulgentes Epling (1939: 273); hence, merging both sections into one, but leaving the former species of sect. Cardinales , not morphologically cohesive with S. cardinalis , out. The new section suffered an additional arrangement due to the transfer of the Mexican species formerly in sect. Nobiles by dos Santos (1991), who justified it supported on morphological evidence to circumscribe the section only to South American species.

According to the current delimitation of the section and based on the combination of characters of the former section Cardinales and Mexican species of Nobiles , Salvia sect. Holwaya includes herbs and suffrutescent herbs, with simple or branched hairs, ovate leaves, acuminate at apex, mostly rounded to cordate/subcordate at base, floral axis with many flowers, bracts early deciduous, large, 5 or 7-veined upper calyx lip, brightly red, pink to magenta colored, showy red corolla, tube papillate or epapillate near the base, frequently invaginate and ventricose, stamens included, connective ornated with a tooth, and pilose style ( Epling 1939, Ramamoorthy 1984, González-Gallegos & Aguilar-Santelises, Bedolla-García & Zamudio 2017). It is currently made up of 10 species: S. adenophora Fernald (1900: 538) , S. disjuncta Fernald (1900: 533) , S. gesneriiflora Lindley & Paxton (1853: 49) , S. guevarae Bedolla & Zamudio (2017: 6) , S. holwayi Blake (1920: 113) , S. karwinskii Bentham (1833: 725) , S. involucrata Cavanilles (1793: 3) , S. stolonifera Bentham (1840: 70) , S. wagneriana Polakowski (1875: 591) , S. tilantongensis González-Gallegos & Aguilar-Santelises (2014: 13) . However, it is necessary to wait for the progress of phylogenetic studies to definitively locate the species; now, most of the sequenced species of the Holwaya section are nested in the Fulgentes clade (Fragoso et al. 2018). This clade groups members of the sections Fulgentes, Holwaya, and Flocculosae ( Epling 1935: 77) Epling (1939:153); in the near future, it is possible that it will be recognized as a monophyletic group.

Among the species of sect. Holwaya, Salvia dugesiana is morphologically most similar to S. karwinskii , particularly with regard to the appearance of the leaves, inflorescence size, number of the flowers per floral node, presence of glandular-capitate hairs along floral axis and calyx, upper lip acuminate and then long caudate, and corolla tube slightly ventricose. Salvia dugesiana differs by having stems and leaves moderately pilose with simple hairs (vs. tomentose with dendritic hairs), lacking bracteoles additional to floral bracts, corolla tube not invaginated (vs. invaginated) and internally epapillate (vs. papillate) (see Table 1 and Fig. 2 for more details; Epling 1939, Klitgaard 2012, Martínez-Gordillo et al. 2019). Furthermore, if S. karwinskii is discarded due to its indumentum with branched hairs, S. dugesiana groups with a set of three Mexican shrubby Salvia surpassing 80 cm tall, having petioles and leaf blades longer than 10 mm and 25 mm, respectively, calyces longer than 11 mm, 5 or 7-veined upper calyx lip, corolla tube ventricose, 20 mm long or longer, epapillate inside, and included stamens: S. guevarae , S. gesneriiflora and S. tilantongensis ; all in fact, members of sect. Holwaya. Considering these three species, S. dugesiana is most similar to S. guevarae due to the corolla tube shorter than 3 cm long, and relatively small corolla lips (upper 7–10.3 mm long, lower 6–12 mm long, vs. 16–25 mm long and 12–27 mm long). Salvia dugesiana can be set apart from S. guevarae by means of the cuneate to oblique leaf base (vs. slightly truncate, rounded to cordate), caudate calyx lobes (vs. short acuminate), narrower corolla tube (6.3–8.7 mm vs. 9–13 mm long) and filiform staminodes (vs. claviform) ( Fig. 2 ). Besides, S. guevarae grows in temperate forest rather than in tropical, including pine-oak and cloud montane forests and has not been recorded in Guanajuato but in Hidalgo, Querétaro and San Luis Potosí.

Alfred Dugès contributed greatly to documenting the Mexican biodiversity thanks to his extensive collections, mainly in the central area of the country, a territory known as El Bajío Region. Unfortunately, most of his samples lack a precise description of the locality or even a simple reference to a town or geographical accident that could be located. The above makes difficult to trace and have an idea of his exploration itineraries, and that is why there was no clue about where to look for S. dugesiana , what in turn promoted taxonomic turmoil that made botanists to hesitate on the recognition of this species. Proof of the later is that the species was overlooked in floristic inventories in Guanajuato ( Carranza-González 2005, Zamudio & Galván-Villanueva 2011), or even in a global checklist of vascular plants in Mexico (Villaseñor 2014). However, the rediscovery of a population of the species makes clear that this deserve to be recognized, being a distinctive species within salvias with red corollas, a taxon that should be added to the list of those taxa restricted to the biogeographical province of the Trans-Mexican Volcanic Belt ( Rzedowski 2020). It is worth noting that S. dugesiana is not the only reported case of a species described based on Dugès specimens and lost for over 100 years; Pachyphytum brevifolium Rose in Britton & Rose (1905: 12) represents an additional example, a plant rediscovered a couple decades ago by Pérez-Calix & Glass (1999) in surrounding areas to the capital city of the state, Guanajuato.

The rediscovery of S. dugesiana was possible only to the fortunate event that the iNaturalist (known as Naturalista in Mexico) user betootero (Roberto Otero Zaragoza) uploaded and observation of the plant, which triggered our attention in its possible identity as this long-forgotten species. This is especially true considering the lack of information commented before, as well as the morphological characters of S. dugesiana and similarity with species of cloud montane, pine-oak and oak forests, what suggested that the species should be found also in that kind of vegetation and not in tropical dry forests. However, there are no elements to ensure that the population in Huanímaro corresponds to the type locality of the species. In the literature and different sources consulted in search of additional information that could clarify some of the localities visited by Dugès, the direct mentions to any geographical name are scarce ( Bean 1892, Biodiversity Heritage Library 2023a, 2023 b, Harvard University & Libraries 2023, IBdata v· 2023, SEINet 2023, Smithsonian National Museum of Natural History 2023). The only localities extracted from that sources and which undoubtedly were visited by Dugès in El Bajío Region and adjacent areas are: Guadalajara in Jalisco state; Cuitzeo, Morelia, Tangancícuaro and Tengüecho in Michoacán state; Campo Santo de [graveyard of] San Sebastián (most probably the one in the city León), Hacienda de Tupátaro, Moroleón, Pénjamo, Santa Rosa mountains, Silao, Tarandacuao and Yuriria lake in Guanajuato state, as well as the capital city with the same name (referring a couple of specific points in the surroundings of the city, or between this and Santa Rosa, Presa de la Olla and San Nicolás Mountain). Of all the listed localities the closest one to Huanímaro is Pénjamo, about 24 km straight line distance ( Fig. 2 ), and being historically a bigger settlement than Huanímaro at the foot of a more massive mountain, it is highly probable that Dugès collected the original material in that mountains. Hence, future botanical exploration in that range might result in additional populations of S. dugesiana .

Figures

FIGURE 1. Distribution map of Salvia dugesiana (triangle) and those localities visited by A. Dugès in Guanajuato state (circles). Guanajuato and Pénjamo cities are highlighted with an asterisk to serve as reference.

FIGURE 2. A. Habitat, B. Above leaf blade, C. Beneath leaf blade, D. Inflorescence, E. Detail of the floral node and lateral view of the corolla, F. Detail of the lowermost floral bracts, G. Lateral view of the corolla, H. Style and connective, I. Immature mericarps. Photographs taken by Brenda Bedolla (A, F, G, I), Jesús G. González-Gallegos (B–E, H).