Hechtia gypsophila López-Ferr., Espejo & Hern., 2019

Hernández-Cárdenas, Rodrigo Alejandro, López-Ferrari, Ana Rosa & Espejo-Serna, Adolfo, 2019, Two new species of Hechtia (Bromeliaceae, Hechtioideae) from Oaxaca, Mexico, Phytotaxa 397 (4), pp. 280-290 : 281-282

Hechtia gypsophila López-Ferr., Espejo & Hern. -Cárdenas, sp. nov. ( Figs. 2 , 4 C–D , 5 , Table 1)

The new species is similar to H. pumila but differs in: the length of the marginal spines of the leaves (2–2.5 vs. 1–2 mm), the arrangement of staminate flowers (dense vs. lax), the size of its floral bract (3–3.5 × 2–2.5 vs. 1–2.5 × 0.8–2 mm), the size of its sepals (1.8–2 × 1–1.5 vs. 1.1–1.8 × 0.7–1.3 mm), the length of its petals (3–3.5 vs. 2–3 mm), the shape of its petals (elliptic vs. sub-spatulate); the length of the floral bracts of the pistillate flowers (2.5–3 vs. 1.1–2.5 mm), and the length of fruits (6.5–8 vs. 3.1–5.5 mm).

TYPE:— MÉXICO. Oaxaca: District of Santiago Juxtlahuaca, municipio of Santiago Juxtlahuaca, lomas yesosas en los alrededores de Laguna Encantada, 5 km después de Santiago Juxtlahuaca rumbo a Huajuapan de León (17°22’11.3” N, 98°01’17.6” W), 1714 m, Julio 17, 2013, fecha de prensado: Mayo, 2015, A. Espejo, A. R. López-Ferrari, J. Ceja-Romero, A. Mendoza-Ruiz y M. I. Mejía- Marín 7564 ♀ (holotype UAMIZ!; isotype MEXU!) .

Plants terrestrial, in flower 70–130 cm high, rosettes ca. 25 cm high, 25–30 cm diameter, caespitose, forming medium to large colonies. Leaves 15–30 in number, ascending to spreading with age; sheaths brown towards the apex, becoming lustrous white to the base, transversely oblong, 2–3 cm long, 3–3.5 cm wide, with tiny marginal spines and scales on the apical portion, glabrous near the base and lepidote toward distal end on both surfaces; blades green, narrowly triangular, 17–30 cm long, 1.5–2 cm wide at base, long attenuate, densely lepidote on abaxial surface, lepidote near the base and glabrous towards the apical region on adaxial surface, lustrous, the margins armed with antrorse or divaricate (split) spines, yellowish-brown, 2–2.5 mm long, 2–2.5 mm wide, 0.8–1 cm apart. Inflorescences in both staminate and pistillate plants terminal, erect to slightly arched and once branched. Staminate inflorescences 90–110 cm tall; peduncle brownish, terete, 4.5–6.5 mm in diameter, glabrous, internodes 2–3.5 cm long; peduncle bracts the lower ones foliaceous, green, narrowly triangular, long attenuate, exceeding the internodes, densely gray-lepidote on both surfaces, gradually decreasing in size distally, the upper ones papyraceous, brownish, triangular, acute, shorter than the internodes, glabrous on both surfaces; primary bracts, brownish, triangular, 6–12 mm long, 4–8 mm wide when extended, acute, margins entire and slightly hyaline, glabrous on both surfaces; spikes 18–30 in number, cylindrical, 2.5–7 cm long, 0.7–1 cm in diameter; floral bracts hyaline, ovate to triangular, 3–3.5 mm long, 2–2.5 mm wide, longer than the pedicel, acute, margins erose, glabrous on both surfaces. Staminate flowers numerous, polystichous, densely arranged; pedicel less than 1 mm long; sepals white tinged with purple-brown at the apex, ovate, 1.8–2 mm long, 1–1.5 mm wide, acute, entire, glabrous on both surfaces; petals white, elliptical, 3–3.5 mm long, 1.5–2 mm wide, rounded at the apex, entire; stamens equal in length; filaments white, linear, flattened, 2–2.2 mm long; anthers yellowish green, oblong, ca. 0.8–1 mm long, versatile; pistillode inconspicuous, white, conical, ca. 0.5 mm long. Pistillate inflorescences 78–135 cm tall; peduncle brown, terete, 3.5–5.5 mm in diameter, glabrous, internodes 2.5–4 cm long; peduncle bracts the lower ones foliaceous, straw-colored to green, narrowly triangular, acute, densely gray-lepidote on both surfaces, gradually decreasing in size distally, the upper ones papyraceous, brownish, triangular to narrowly triangular, long attenuate, entire, shorter than the internodes, glabrous on both surfaces; primary bracts papyraceous, triangular, 6–15 mm long, 5–8 mm wide when extended, acute, entire and slightly hyaline at the margins, glabrous on both surfaces; spikes 7–30 in number, cylindrical, 1–3 cm long, 0.8–1 cm in diameter; floral bracts white tinged with purple-brownish, ovate to triangular, 2.5–3 mm long, 1.5–2 mm wide, acute, erose at the margins, glabrous on both surfaces. Pistillate flowers numerous, polystichous, densely arranged; pedicel less than 1 mm long; sepals white-greenish tinged with purple at the apex, triangular, 2–2.5 mm long, 1.5–2 mm wide, acute, erose at the margins, glabrous on both surfaces; petals white, ovate to triangular, 3–3.2 mm long, 1.5–2 mm wide, obtuse, entire; staminodes rudimentary, white to brownish-white, narrowly triangular, ca. 1.8 mm long; ovary green, cylindrical, 3–4 mm long, 0.5–1.5 mm diameter, glabrous; stylar branches greenish-brown, recurved, slender, stigma papillose. Capsules green when young, brownish when mature, ovoid, 6.5–8 mm long, 3–4.5 mm diameter with a pedicel of ca. 1 mm long.

Distribution and habitat: — Hechtia gypsophila is only know from the northwest region of the state of Oaxaca in the municipality of Santiago Juxtlahuaca ( Figure 5 ), where it grows on gypsum soils in xerophytic scrub and tropical deciduous forest with presence of species of Bursera Jacq. ex L., Juniperus L., and Fabaceae Lindl. , at elevations between 1620 and 1720 m. Plants of H. gypsophila blooms from May to August and grow in medium to large colonies with abundant individuals of Anemia colimensis Mickel (1962: 434) , Cheiloplecton rigidum var. lanceolatum Mickel & Beitel (1988: 124) , Myriopteris aurea Grusz & Windham (2013: 55) , Pinguicula medusina Zamudio & Studnicka (2000: 68) , and Selaginella pilifera Braun (1857: 20) .

Etymology: —Specific epithet refers to the gypsum soils in which the plants are growing.

Additional specimens examined (paratypes): — MÉXICO. Oaxaca: Distrito Santiago Juxtlahuaca, municipio de Santiago Juxtlahuaca . Laguna Encantada, muy cerca de Juxtlahuaca, 17°21.92’ N, 98°01.21’ W, 1620 m, Agosto 19, 1994, C. Glass et al. 8418 ♂ ( IEB!) ; Oaxaca: Distrito Santiago Juxtlahuaca, municipio de Santiago Juxtlahuaca. Laguna Encantada, ± 3 km al N de Santiago Juxtlahuaca , 1650–1700 m, Mayo 27, 1999, S. Zamudio y G. Ocampo 11049 ♂ ( UAMIZ!) .

Observations: —Specimens of Hechtia gypsophila have previously been collected in August 1994 in the surroundings of Laguna Encantada, in the municipality of Santiago Juxtlahuaca by C. Glass et al. 8418 (MEXU), but misidentified as Hechtia conzattiana . However, H. gypsophila differs from H. conzattiana in the length of the leaves (17–30 vs. up to 37 cm), the arrangement of the flowers in the inflorescence (dense vs. lax), the length of the floral bracts (3–3.5 vs. 2–2.5 mm), and the shape of the sepals (ovate vs. broadly elliptic). Type localities of H. flexilifolia , H. nuusaviorum and H. oaxacana are close to that of H. gypsophila but the plants of these species clearly differs from those of the new taxon in vegetative and reproductive characters, like the size of the rosettes, the length of the foliar blades, the presence or not of indumentum on the peduncle, and the size and arrangement in the inflorescence of staminate and pistillate flowers (see Table 1). Hechtia gypsophila grows exclusively on gypsum soils and is characterized by its glabrous peduncle of both staminate and pistillate inflorescences, and by flowers with shortly pedicel (less than 1 mm long).

Figures

FIGURE 2. Hechtia gypsophila López-Ferr., Espejo & Hern.-Cárdenas. A. Rosettes in habitat at the type locality. B. Group of pistillate plants at the type locality. C. Group of rosettes. D. Detail of the pistillate inflorescence. E. Pistillate spike. F. Pistillate flower. G. Floral bract. H. Sepals. I. Petals. J. Pistil. (Photographs A–E by A. Espejo-Serna; F–J by R. Hernández-Cárdenas).

FIGURE 4. Herbarium specimens of Hechtia gypsophila spec. nov. and H. minuta spec. nov. A. Staminate plant of Hechtia minuta (Hernández-Cárdenas et al.2155). B. Pistillate plant of H. minuta (Hernández-Cárdenas et al. 2155bis). C. Pistillate plant of H. gypsophila (Espejo et al. 7564). D. Staminate plant of H. gypsophila (Zamudio y Ocampo 11049).

FIGURE 5. Distribution map of Hechtia flexilifolia I. Ramírez & Carnevali, H. gypsophila López-Ferr., Espejo & Hern.-Cárdenas, H. minuta Hern.-Cárdenas, Espejo & López-Ferr., H. nuusaviorum Espejo & López-Ferr., H. oaxacana Burt-Utley, Utley & García-Mend., and H. pumila Burt-Utley & Utley.