Hechtia subalata L.B. Sm., Contribution Gray Herbarium

Ramírez-Morillo, Ivón, Carrillo-Reyes, Pablo, Tapia-Muñoz, José Luis & Ramírez-Díaz, Claudia J., 2021, In disentangling two species limits of Hechtia (Bromeliaceae: Hechtioideae) from Sierra Madre Occidental, a new species is discovered from Durango, Mexico, Phytotaxa 523 (1), pp. 55-72 : 67-68

Hechtia subalata L.B. Sm., Contribution Gray Herbarium 117: 15–16, t. 1, f. 29. 1937.

TYPE:— MEXICO: Durango, Sierra Madre , August 13, 1897, J. N. Rose 3467 fruits (holotype, US!; photograph and fruits , GH!) .

EPITYPE (designated here):— MEXICO: Zacatecas: Municipio Valparaíso, 1 km SE del Puente Tepetatita , 26 km W de Huejuquilla el Alto rumbo a San Juan Capistrano, 22°40’36.1’’N, 104°03’03.3’’W, 1078 m, matorral xerófilo con Prosopis, Jatropha , Croton , Myrtillocactus , originally collected May 27, 2015 by P. Carrillo-Reyes, J.L. Tapia, C.J. Ramírez-Díaz and I. Ramírez; flowering in cultivation in 2019, I. Ramírez et al. 2430♂ (epitype CICY! ; isoepitypes, IBUG!, MEXU!) .

Plants lithophytic, cespitose, 1.4–1.8 m when flowering; rosettes in general shape globose, 40–60 cm tall, 50–60 cm in diameter, generally forming dense, small colonies of 2–6 rosettes, rarely clumps of 8–12 rosettes. Leaves 20–35 in number, central ones erect, basal ones slightly reflexed; sheath broadly ovate to widely elliptical, 4–5.2 × 4.5–7 cm, margins entire to erose toward the apex, lustrous and glabrous at the base adaxially and slightly lepidote at the apex, white lepidote abaxially; blade narrowly triangular, acuminate to long attenuate, 20–50 × 2.5–4.8 cm, green, sometimes with red spots at the apex and or margins, at the base of every spine, densely white lepidote abaxially, white lepidote at base but soon glabrous and glossy adaxially; marginal spines retrorse rarely antrorse, triangular, 1.5–2.5 mm long, 0.8–2.5 cm apart, light brown or occasionally with red spots close to the spines. Inflorescence central, erect, emerging from a fully grown rosette (strict sympodium growth pattern, type SPP sensu Ramírez-Morillo et al. 2014).

Staminate inflorescences a once-divided panicle, cylindrical in general shape, erect, 0.65–1.8 m long; peduncle terete, green to brownish, sparsely lepidote, 20–56 cm long, 5–14 mm in diameter at the base, surpassing the rosette; internodes (0.8–) 1.1–4.8 cm long; peduncle bracts the basal ones with wide-ovate sheath, 1–2.2 × 1.1–7 cm, the blade narrow triangular, long attenuate, slightly pungent, (3.5–)8.7–17 × 0.3–0.7 cm, green to brownish, the apical ones without a clear distinction between sheath and blade, ovate to triangular, long attenuate to acuminate, 2.2–4.5 × 0.8–1.1 cm, margins entire to erose and spiny toward the blade multi-nerved, brownish when dry, white lepidote abaxially, glabrate adaxially, longer than internodes; rachis (main axis) 0.44–1.32 m long, 5–10 mm in diameter at the base, terete, brownish; internodes 1–3.4 cm long; primary bracts ovate-triangular, acuminate, 1.2–4 × 0.8–1.4 cm, entire to dentate, light brown, densely lepidote abaxially, slightly lepidote adaxially, multi-nerved, shorter than branches; branches 16–59 in number, forming an angle of 45° or less with the rachis, 2.5–10 (–15) cm long, ca. 1.5 cm in diameter, 28–72 flowered; rachis (branch) terete, light brown, 7–8 cm long, 0.8–1.2 mm in diameter, densely lepidote, stipe nearly none; floral bracts broadly ovate, acute, 4.5–6 × 2.5–4.5 mm, brown, margins erose to dentate, glabrous on both surfaces, multi-nerved, sometimes with a conspicuous central nerve, equaling or slightly surpassing the sepals. Flowers sessile, polystichous, divaricate, fragrant during the morning (sweet smell); sepals ovate to triangular, acute, cucullate, 3–4 × 2–2.5 mm, entire to slightly erose, brownish, glabrous on both surfaces, multi-nerved; petals elliptical, acute to rounded, cucullate at the apex, 4–5 × 2–3 mm, white with brown spots, glabrous on both surfaces, multinerved; stamens exserted, ca. 4.5 mm long; filaments triangular, flattened, ca. 4 mm long, white; anthers oblong, 2–3 mm long, dorsifixed, yellow, pollen yellow; pistillode reduced, 1.5 × 2 mm, stigmatic lobes much reduced.

Pistillate inflorescences a once-divided panicle, cylindrical in general shape, erect, 1.2–1.7 m long; peduncle terete, 0.35–1.18 m long, 8–20 mm in diameter at the base, surpassing the rosette; internodes (1–) 2–4 cm long; peduncle bracts the basal ones with triangular sheath, 1.5–25 × 1.4–1.8 cm, the blades narrow triangular, long attenuate, slightly pungent, 10–27 × 0.5–0.7 cm, foliaceous, green to brownish, the apical ones without a clear distinction between sheaths and blades, ovate to triangular, 2–3.5 × 0.9–1.2 cm, margins entire to erose and spiny toward the blade, long attenuate to acuminate, brownish when dry, white lepidote abaxially, glabrate adaxially, multi-nerved, longer than internodes; rachis (main axis) 63–73 cm long, 6–9(–14) mm in diameter at the base, terete, green; internodes (1–) 2–3.5 cm long; primary bracts triangular, acuminate, 1.5–2.5 × 0.8–1.5 cm, light brown, glabrous on both surfaces, entire to dentate, multi-nerved, shorter than branches; branches 22–32 in number, forming an angle of 45° or less with the rachis, (2–) 5–15 cm long, 4–8 mm in diameter, with 10–44 flowered, flowers occasionally emerging from the base of the branch; rachis (branch) terete, green, 0.4–0.8 cm long, 2–4 mm in diameter, glabrescent, stipe nearly none; floral bracts broadly ovate, acute, 3–4.5 × 3–4 mm, without covering or exceeding the sepals, margins erose to dentate, glabrous on both surfaces, multi-nerved, sometimes with a conspicuous central nerve, brown, membranous. Flowers sessile, polystichous, divaricate, fragrant (sweet smell during the morning); sepals ovate, acute, 2–3.5 mm long, ca. 2.5 mm wide at the base, entire, green to brownish, glabrous on both surfaces, multi-nerved; petals triangular, acute, cucullate at apex, 3–4.5 mm long, ca. 2 mm wide at the base, entire, white with brown spots, multi-nerved; staminodes six in number, triangular, laminar, 1.5–2 mm long, ca. 0.5 mm wide, inserted in the corolla; ovary superior, oblongoid to ellipsoid, ca. 7 mm long, 3 mm in diameter, light green, glabrous, stigmatic lobes recurved, ca. 1 mm long, light green, placentation axillary. Fruits ellipsoid, 9–15 mm long, 6–7 mm in diameter, glabrous, erect, brown when dry; s eeds narrowly triangular, brown, 3.5–4 mm long, 1 mm wide, caudate, apical wing ca. 2 mm long, basal wing reduced, brown.

Additional specimens examined: — MEXICO. Jalisco: Municipio Huejuquilla el Alto, 3.6 km al NW del poblado Los Arroyos del Agua , km 17.5 de la carretera Huejuquilla el Alto-Ruiz, 22º40’30.7’’ N, 103º59’21.2’’ W, 1260 m, October 6, 2018, D. Figueroa et al. 235♂ ( IBUG), 236♀ ( IBUG!); Municipio Bolaños, Bolaños , orilla del pueblo, 21°49’48.0”N, 103°46’48.0”W, 885 m, November 7, 2018, K. Romero-Soler et al. 1239 fruits ( CICY!, IBUG!), 1240♂ ( CICY!); Municipio Chimaltitán, foothills 8–12 km SW of Bolaños, R. McVaugh 25929♀ ( MICH!); Municipio Mezquitic, 3 km al E de Tetakararo, bajando la barranca, 800 m, November 10, 1985, C. Chávez-Reyes D. 169♀ ( IBUG!); Municipio San Martín de Bolaños, 1 km al S del Rancho La Joya , brecha San Martín al Platanito, 900 m, May 18, 1989, A. Flores et al. 1583 fruits ( XAL!); Municipio Villa Guerrero, 11.2 km al oeste de Villa Guerrero camino a Bolaños , 21°58’03”N, 103°40’36”W, 1780 m, November 6, 2018, K. Romero-Soler et al. 1238 fruits ( CICY!); 11.2 km al WSW de Villa Guerrero por la carretera a Bolaños (7.7 km en línea recta), 21°58’03”N, 103°40’36”W, 1780 m, April 4, 2017, P. Carrillo-Reyes et al. 8520 fruits ( IBUG!). Nayarit: Municipio El Nayar, arroyo El Fraile , al SE de la Mesa del Nayar, 22°09’N, 104°33’W, 520 m, October 23, 1989, P. Tenorio & G. Flores 16620♀ ( MEXU!, MO!); Vereda de la Mesa del Nayar al Cangrejo, que cruza por la barranca, 900–1400 m, August 5, 1990, R. Ramírez et al. 551♀ ♂ ( MEXU!). Zacatecas: Municipio Valparaíso, 1 km SE del Puente Tepetatita, 26 km W de Huejuquilla el Alto rumbo a San Juan Capistrano , 22°40’36.1’’N, 104°03’03.3’’W, 1078 m, May 27, 2015; flowering under cultivation in 2018, I. Ramírez et al. 1989 fruits ( CICY!); I. Ramírez et al. 1989 a ♂ ( CICY!, IBUG!, MEXU!); San Juan Capistrano , August 23, 1883, J. Rose 3556 fruits ( HUH!, NY!); 16.8 km al W de Huejuquilla rumbo a San Juan Capistrano, alrededores del río Atengo o Chapalagana , 1019 m, March 24, 2010, A. Castro-Castro 2027♀ ( IBUG!); Valley of río Atenco (Chapalagana) , 8–15 km northeast of San Juan Capistrano , road to Huejuquilla el Alto, sheltered rocky canyon, and adjoining arid flats, 1000–1200 m, January 14, 1975, R. McVaugh 25795♀ ( MEXU!); 6 miles before San Juan Capistrano on road to Jesus María, 1036 m, January 22, 1976, M. Kimnach 1855♀ ( MEXU!); aprox. 2 km antes de llegar a Chimaltitán , después de Florencia, 790 m, May 20, 1985, J.A. Lomelí-Sención 85-00190 ♂ ( GUADA!) .

Phenology:—Staminate plants have been collected in January, March, August, October and November; female flowers are documented during May, August, October, and November; while fruits have been collected during April, May, August, and November.

Distribution and habitat:— Hechtia subalata has been collected in the Mexican States of Durango (Municipality of Mezquital), Jalisco (Bolaños, Chimaltitán, Huejuquilla el Alto, San Martín de Bolaños, and Mezquitic and Villa Guerrero Municipalities), Nayarit (Del Nayar Municipality) and Zacatecas (Valparaíso Municipality). According to the biogeographical provinces of Morrone et al. (2017), this taxon occurs in the Pacific Lowlands province, particularly in canyons that penetrate the Sierra Madre Occidental province ( Figure 1 ), at 800–1300 m of elevation, growing on rocky slopes, within tropical dry forest, xerophytic shrubland and ecotones between those vegetation types with species of Agave , Bursera bipinnata (DC.) Engl. , B. fagaroides, Coryphantha (Engelm.) Lem. , Croton L., Dodonaea viscosa (L.) Jacq., Echinocereus pamanesiorum Lau , Euphorbia schlechtendalii Boiss. , Forestiera phillyreoides (Benth.) Torr. , Heliocarpus terebinthinaceus (DC.) Hochr. , Ipomoea murucoides Roem. & Schult. , Leucaena Benth. , Myrtillocactus geometrizans (Mart. Ex Pfeiff.) Console , Opuntia , Prosopis laevigata (Humb. & Bonpl. ex Willd.) M.C. Johnst. , Stenocereus queretaroensis , and Vachellia pennatula (Schltdl. & Cham.) Seigler & Ebinger ( Figure 6 ).

IUCN Conservation assessment:— Hechtia subalata is known from 17 collections (ten localities); most of them by roadsides, and most likely occurs as isolated populations on appropriate microniches, rocky slopes in rugged canyons. It has values of EOO de 6592.7 km ² and an AOO of 44 km ². According to the IUCN, therefore this species should be considered as Vulnerable (VU) to Endangered (EN); nevertheless, because of the lack of population information, we rely mostly upon distributional data, namely, the set of B criteria, geographical distribution.

Discussion: —Species of Hechtioideae , in general and those of Hechtia in particular, are still poorly represented in herbaria: nothing is more discouraging for the collector than spiny, usually large rosettes with large inflorescences. Most collectors usually find species in fruit because flowers last only one day and even inflorescences with tens or hundreds of flowers, last but a few days. It is also known that populations of some species do not bloom every year, especially those with strict monocarpic growth pattern (SMP, sensu Ramírez-Morillo et al. 2014) where long-lived, well-developed rosettes take years to produce an inflorescence (for example Hechtia zamudioi Espejo, López-Ferr. & I. Ramírez (2008: 55)) . Species more frequently found in bloom, year after year, are those with sympodial growth, with precocious-flowering pattern (i.e. Hechtia rosea E. Morren ex Baker (1889: 140)) . We still do not know what triggers plants to produce inflorescences. In the case of Hechtia subalata , as for ca. 26% of the described species, type specimens only have fruits, and few of them included additional information on flowers or rosettes in their protologues. For H. subalata , few features are discernable in the holotype (fruit size, inflorescence branching, branch length, etc.) or the paratype (foliar blade, particularly the margins: sinuose-concave between spines, and spines alternating on both margins). These data, combined with its geographical distribution, allow us to finally complete our understanding of this concept and assign a more precise (other than what is found in type specimens) geographical distribution. It is important to mention that the female flowers of H. subalata ( Figure 7B ) are practically identical to those of H. jaliscana ( Figure 3E ), but their arrangement on the branches (agglomerated in the first and lax in the second) differentiates these two taxa. It is important to emphasize that this close similarity of female flowers between both species is another reason to propose epitypites based on a staminate specimen.

Figures

FIGURE 1. Geographical distribution of Hechtia jaliscana, H. marthae and H. subalata. Biogeographical provinces are depicted in different colors; their limits are based on Morrone et al. (2017).

FIGURE 3. Hechtia jaliscana. A. General structure of a male individual in bloom. B. Bee visiting fragrant male flowers. C. Origin of the inflorescence in a female plant. D. Details of male flowers. E. Details of female flowers. F. Branch with male flowers. G. Branch with female flowers. H. Preserved ripe fruits.(Credits:A, D, F. Claudia Ramírez-Díaz. B, C. Ivón Ramírez-Morillo.E, G. Pablo Carrillo-Reyes. H. Fruit features taken from P. Carrillo-Reyes & D. Cabrera-Toledo 8880-A♀ (IBUG)).

FIGURE 6. Hechtia subalata: A. Detail of the branching with young fruits. B. Detail of a dry staminate inflorescence. C. Rosette with infructescence. D. Plants in habitat, showing the red coloration on leaves. (Credits: A, C. Sabina Ascencio. B. Ivón Ramírez-Morillo. D. Pablo Carrillo-Reyes).

FIGURE 7. Hechtia subalata portraying a rosette in bloom, note the red coloration on the leaves. A. Pistillate inflorescence. B. Female flowers at anthesis. C. Branch with open fruits. D. Staminate inflorescence. E. Details of the male flowers with open exposing the pollen. F. Open flowers before anthesis. (Illustration by Alberto Guerra based of photographs by A, B. Omar Góngora. C-F, Ivón Ramírez- Morillo).