Hechtia minuta Hern-Cárdenas, Espejo & López-Ferr., 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 : 282-288

Hechtia minuta Hern-Cárdenas, Espejo & López-Ferr. , sp. nov. ( Figs. 3 , 4 A–B , 5 , Table 1)

The new species is similar to H. pumila but differs in the length of the marginal spines of the leaves (3–4 vs. 1–2 mm), the arrangement of staminate flowers (dense vs. lax), the length of its floral bracts (2.5–3 vs. 1–2.5 mm), the size of its sepals (2–2.2 × 1.3–1.5 vs. 1.1–1.8 × 0.7–1.3 mm), the shape of its sepals (elliptic vs. ovate), the shape of its petals (elliptic vs. sub-spatulate); the length of the floral bracts of the pistillate flowers (3–4 vs. 1.1–2.5 mm), the length of its sepals (2.5–3 vs. 1.3–2.5 mm long), the shape of its petals (oblong vs. ovate-triangulate), and the length of fruits (8–9 vs. 3.1–5.5 mm).

TYPE:— MÉXICO. Oaxaca: Distrito Santiago Juxtlahuaca, municipio Santos Reyes Tepejillo. En los alrededores del Boquerón de Santos Reyes Tepejillo (17°26’58” N, 97°56’29” W), 1960 m, Abril 21, 2018, R. Hernández-Cárdenas, E. Negri y J. Conde 2155 ♂ (holotype UAMIZ!; isotype MEXU!) .

& 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.

Plants terrestrial or saxicolous, in flower 70–130 cm tall, rossetes 5–7 cm high, 9–12 cm in diameter, caespitose, forming medium to large colonies. Leaves 15–25 in number, recurved towards the apex; sheaths brownish at the apex, white towards the base, quadrangular to transversely oblong, 2–4.5 cm long, 2–4.5 cm wide, with tiny marginal spines distally, glabrous near the base and lepidote toward distal end on both surfaces; blades yellowish-green to yellowish-red, narrowly triangular, 5–13 cm long, 2–4 cm wide at the base, long attenuate, densely lepidote on abaxial surface, lepidote near the base and glabrous towards the apical portion on adaxial surface, margins with antrorse or divaricate (split) spines, yellowish-brown, 3–4 mm long, 2.5–3 mm wide, 1–1.5 cm apart. Inflorescences in both staminate and pistillate plants terminal, erect to slightly arched and once branched. Staminate inflorescences 70–100 cm high; peduncle brownish-green, terete, 4–5 mm in diameter, glabrous, internodes 1.5–3 cm long; peduncle bracts the lower ones foliaceous, narrowly triangular, long attenuate, exceeding the internodes, gray-lepidote on abaxial surface, lepidote near the base, and glabrous towards the apical portion on adaxial surface, gradually decreasing in size distally, the upper ones papyraceous, brownish, triangular, attenuate, shorter than the internodes, glabrous on both surfaces; primary bracts brownish, triangular, 8–13 mm long, 6–8 mm wide when extended, acute, margins entire and slightly hyaline, glabrous on both surfaces; spikes 18–30 in number, terete, 2–6 cm long, 0.6–1 cm diameter; floral bracts brownish, ovate to triangular, 2.5–3 mm long, 1.5–2 mm wide, longer than the pedicel, acute, margins erose and hyaline, glabrous on both surfaces. Staminate flowers numerous, polystichously arranged, densely arranged; pedicel ca. 1 mm long; sepals greenish white at the base, brownish white at the apex, elliptic, 2–2.2 mm long, 1.3–1.5 mm wide, acute to rounded at the apex, margins entire to erose, glabrous on both surfaces; petals white to brownish, elliptic, 2–2.5 mm long, 1.5–2 mm wide, rounded at the apex, entire; stamens equal in length; filaments white, linear, flattened, 0.8–1 mm long; anthers yellowish tinged with purple to green, oblong, ca. 0.8–1 mm long, versatile; pistillode inconspicuous, white, conical. Pistillate inflorescences 120–130 cm high; peduncle brownish, terete, 5–7 mm in diameter, glabrous, internodes of 1–3 cm long; peduncle bracts the lower ones foliaceous, narrowly triangular, gray-lepidote on abaxial surface, lepidote near the base and glabrous towards the apical portion on adaxial surface, gradually decreasing in size distally, attenuate, entire and hyaline at the margins, the upper ones papyraceous, brownish, triangular to narrowly triangular, acute, shorther than the internodes, glabrous on both surfaces; primary bracts papyraceous, brownish, triangular, 6–10 mm long, 4–6 mm wide when extended, acute, entire and slightly hyaline at the margins, glabrous on both surfaces; spikes 7–12 in number, globose to slightly cylindrical, 1–2.5 cm long, 1.2–1.5 cm diameter; floral bracts white or white-brownish, ovate to broadly ovate, 3–4 mm long, 2–3 mm wide, acute, entire to erose at the margins, glabrous on both surfaces. Pistillate flowers numerous, polystichous, densely arranged; pedicel ca. 1 mm long; sepals greenish white tinged purple, ovate, 2.5–3 mm long, 1.5–2 mm wide, obtuse, entire, glabrous on both surfaces; petals white, oblong, 3–3.5 mm long, 1–1.5 wide, obtuse, entire; staminodes rudimentary, white to white-brownish, narrowly triangular, ca. 1.5 mm long; ovary green to green-purplish, cylindrical, 1–2 mm long, 1–18 mm diameter, glabrous; stylar branches white-brownish, recurved, slender, stigma papillose. Capsules greenish when young, brownish when mature, broadly ovoid, 8–9 mm long, 4.5–5 mm diameter, with a pedicel of ca. 1 mm long.

Distribution and habitat: — Hechtia minuta is only know from the municipality of Santos Reyes Tepejillo located in the Sierra Madre del Sur in the northwest region of the state of Oaxaca ( Figure 5 ), where it grows on rocky cliffs and vertical walls, or terrestrially in dry oak forest and tropical deciduous forest ( Rzedowski, 1978) with species of the genera Acacia Mill. , Bursera , Ipomoea L., Lysiloma Benth. , and Quercus L. There is a valley and a big canyon in this area, called Boquerón of Santos Reyes Tepejillo, where plants of H. minuta are growing in colonies on the cliffs of the canyon among other saxicolous plants like Cyrtopodium macrobulbon Romero-González & Fernández-Concha (1999: 331) , Prosthechea micropus Higgins (2004: 223) , P. trulla Higgins (1997: 81) , and Tillandsia dugesii Baker (1887: 278) . Plants of H. minuta inhabit an area at elevations between 1770 and 1960 m and bloom from March to April.

Etymology: —Specific epithet refers to the small size of the plants of this new species.

Additional specimens examined (paratypes): — MÉXICO. Oaxaca: Distrito Santiago Juxtlahuaca, municipio Santos Reyes Tepejillo. En los alrededores del Boquerón de Santos Reyes Tepejillo (17°26’58” N, 97°56’29” W), 1960 m, marzo 1, 2018, R. Hernández-Cárdenas y A. Hernández-Rabago 2145 ♂ ( UAMIZ) ; Oaxaca: Distrito Juxtlahuaca, municipio Santos Reyes Tepejillo. En los alrededores del Boquerón de Santos Reyes Tepejillo (17°26’58” N, 97°56’29” W), 1960 m, Abril 21, 2018, R. Hernández-Cárdenas, E. Negri y J. Conde 2155bis ♀ ( UAMIZ) ; Oaxaca: Distrito Santiago Juxtlahuaca, municipio Santos Reyes Tepejillo, 3 km al N de Santos Reyes Tepejillo rumbo a Corral de Piedra , 17°27’ N, 97°57’ W, 1770 m, Julio 20, 1995, J. I. Calzada 19879 ( MEXU) .

Observations: —Plants of Hechtia minuta had previously been collected in the Mixteca Baja region, in the municipality of Santos Reyes Tepejillo by J. I. Calzada 19879 (MEXU), but had been wrongly identified as Hechtia lyman-smithii . However, H. minuta differs from H. lyman-smithii in the diameter of the rosettes (21.5–27 vs. 9–12 cm), in the length of the pedicel (ca. 1 vs. 0.8–3 mm), and in the arrangement of the flowers (dense vs. lax). Other members of the genus, like H. flexilifolia , H. nuusaviorum and H. oaxacana , are growing in nearby locations to the type locality of H. minuta ( Figure 5 ). However all these species are easily distinguishable from the newly proposed taxon ( Table 1).

Hechtia minuta differs from H. flexilifolia in the length of the foliar blades (5–13 vs. 12–60 cm), in the number of spikes in staminate (18–30 vs. 77–81) and pistillate (7–12 vs. 11–18) plants, and in the arrangement of flowers (dense vs. lax) in the staminate inflorescences. H. minuta differs from H. nuusaviorum in the length of the foliar blades (5–13 vs. 30–75 cm) and in the size of floral bracts, sepals and petals of staminate and pistillate flowers (see Table 1). Finally, H. minuta differs from H. oaxacana in the number of spikes in staminate (18–30 vs. 30–36) and pistillate (7–12 vs. 15–28) inflorescences, in the arrangement of flowers (dense vs. lax) in the staminate inflorescences, in the length of the primary bracts of the staminate and pistillate inflorescences (0.6–1.3 vs. 1.5–2.5 cm), and in the size of the floral bracts of the staminate inflorescences (2.5–3 x 1.5–2 vs. 3–7 x 2.5–5 mm).

In general Hechtia minuta is easily recognized by its small rosettes, never exceeding 15 cm in diameter and 7 cm in height, with yellowish-green to yellowish-red leaves, which are recurved towards the apex; the glabrous peduncle, the sessile densely arranged flowers, and the shape of the sepals and the petals in the staminate (elliptic) and pistillate (ovate and oblong) flowers. Table 1 includes a comparison of more details for H. flexilifolia , H. gypsophila , H. minuta , H. nuusaviorum , and H. oaxacana .

Figures

FIGURE 3. Hechtia minuta Hern.-Cárdenas, Espejo & López-Ferr. A. Group of rosettes in habitat at the type locality. B. Detail of the rosette. C. Plant at the type locality. D. Pistillate spike. E. Spike at fruiting stage. F. Detail of the fruiting spike. G. Detail of the pistillate spike. H. Pistillate flower. H1. Floral bract. H2. Sepals. H3. Petals. H4. Pistil. I. Detail of the staminate inflorescence. J. Staminate spike. K. Staminate flower. K1. Floral bract. K2. Sepals. K3. Petals. K4. Stamens (Photographs B–E, M by E. Negri Lavín; A, F–L, Ñ–S 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.