Hechtia hernandez-sandovalii I. Ramírez, C. F. Jiménez & Treviño, 2013

Morillo, Ivón Ramírez, Jiménez Nah, Carlos F. & Carreón, Jacinto Treviño, 2013, A new species of Hechtia (Bromeliaceae) from southwestern Tamaulipas, Mexico, Phytotaxa 112 (2), pp. 33-42 : 34-40

Hechtia hernandez-sandovalii I. Ramírez, C. F. Jiménez & Treviño , sp. nov. ( Fig. 1 (A,C,E,F), 2, 3).

Species similar to Hechtia glomerata Zucc. in its acaule rosettes with narrowly triangular blades, glabrous above, densely white lepidote below, lateral inflorescence, and staminate and pistillate flowers with white petals. However, H. hernandez-sandovalii presents branches of the inflorescence densely covered with a initially white indumentum that turns brownish with age and flowers totally immersed in it (vs. thin indumentums and flowers not immersed in it), rosettes taller than wide, leaves erect, falcate, laminae green, never developing red color (vs. rosette ellipsoid, wider than tall, leaves horizontally extended, apices deflexed, leaves green, shiny above, usually develop red color in H. glomerata ); foliar sheaths shorter (2.5–3 cm vs. 3–6 cm in H. glomerata ); floral parts (floral bracts, petals, sepals, ovary, anthers, and staminodes) and fruits larger, but seeds smaller in H. hernandez-sandovalii .

TYPE:— MEXICO. Tamaulipas: Municipio de Miquihuana , 17 km al W de Miquihuana camino a Estanque de Los Walle , 23°62’N, 98°57’– 99°06'W, 28 mayo 1986, Hernández & Martínez 1797 ♀ (holotype MEXU! (2), isotypes ( QMEX!, TEX-LL, UAT!).

Terrestrial, caespitose, rosetofilous herbs, when blooming 1–1.80 m tall. Rosettes up to 35 cm diameter, taller than wide, leaves erect, falcate, new rosettes originating at the base of old ones and forming large colonies. Leaves 25–35 per rosette, succulent, straight and pointing upwards, foliar sheaths transversally oblong, 2.5–3 cm long, (2.6–) 3.7–4.8 cm wide, when dry white-yellowish adaxially and brownish abaxially, sometimes with a distally darker brown area, glabrous on both surfaces, basally entire, finely dentate close to the lamina; foliar blades narrowly triangular, acuminate, pungent, 21–39 cm long, 1.3–2.9 cm wide at base, 0.5–1.1 cm wide on the mid area, green, glabrous to sparsely white lepidote adaxially, white lepidote abaxially, margins spinose, spines 4–7 mm long,, uncinate, generally retrorse, (0.8–) 1.6–4.4 (–5.1) cm apart, laxly arranged toward the apex, reddish. Inflorescence lateral, erect.

Staminate inflorescence a 2-divided panicle, 1.15–1.53 m long; peduncle 58–61 cm long, 0.9–1.3 cm diameter, base flattened, light brown, sparsely white lepidote but sometimes glabrous, much longer than leaves; peduncle bracts triangular to triangular-ovate, acuminate, 2.3–6.2 cm long, 1–2.7 cm wide, brownish, sparsely lepidote, finely and laxly denticulate at base, entire towards the apex, strongly nerved, longer than internodes at the base, shorter towards the apex; main axis 57–92 cm long, 0.4–0.8 cm diameter, cylindrical, sometimes slightly sinuose, light brown, sparsely lepidote, soon glabrous; its internodes 1.4–4.8 cm long, shorter towards the base; primary bracts triangular, acute, acuminate, 1–4 cm long, 0.6–1.2 cm wide, brownish, sparsely lepidote, entire, strongly nerved; primary branches ca. 30 per inflorescence, 2–8.3 cm long, 0.8–1.3 cm diameter, sessile, ascending or appressed to main axis, ca. 8–50 (–70) flowers per branch; secondary branches 1.3–2.5 cm long, ca. 10–20 flowers on each branch; floral bract long-ovate, shortacuminate, 6.3–8.2 mm long, 4–4.4 mm wide, brownish, erose, densely white lepidote, 7-nerved, exceeding sepals and petals; flowers densely clustered and covered by a dense white indumentums which is cotton like and becomes brownish with age, 6.5–7.5 mm long, 3–3.2 mm diameter, sessile; sepals connate by ½ of their length, oblong, acute, 4.4–5.3 mm long, 2.3–2.5 mm wide, brownish, erose, densely white-lepidote, 5-nerved, slightly carinate, shorter than petals; petals free, obovate, rounded, 5.5–6 mm long, 2.8–3 mm wide, entire, white, densely white-lepidote, 7-nerved; stamens erect, adnate to the petals and pistillode base, barely protruding at anthesis, 3.2–4 mm long; filaments narrowly triangular, 2.9–3.5 mm long, 0.7 mm wide, white; anthers ca. 2.2 mm long, ca. 0.8 mm wide; pistillode conical, 1.4 mm long including vestigial stigmatic lobes, ca. 1.2 mm diameter, greenish to almost white; vestigial stigmatic lobes narrow, erect, 0.7 mm long.

Pistillate inflorescence a 1–2 divided panicle, 0.73–1.30 m long; peduncle 37–75 cm long, 0.5–0.9 cm diameter, base flattened, reddish or brownish, sparsely white lepidote, soon glabrous, much longer than leaves; peduncle bracts triangular, acuminate, 1.7–6.3 cm long, 0.7–2.6 cm wide, brownish, sparsely lepidote, finely and loosely denticulate at base, entire towards the apex, strongly nerved, longer than basal internodes, equal or shorter on apical ones, its internodes 1.5–2.6 cm long, increasing in length from base to apex; main axis 27–80 cm long, 0.3–0.4 cm diameter, terete, sometimes sinuous, reddish or brownish, sparsely lepidote, sometimes glabrous, its internodes 1.5–5.8 cm long; primary bracts triangular, acuminate, 0.9–3 cm long, 0.7– 1 cm wide, brownish, sparsely lepidote, entire, strongly nerved; primary branches 11–13 per inflorescence, 0.9–4.7 cm long, (0.5–) 0.9–1.7 cm diameter; its rachis 0.15–0.2 cm diameter, basal portion of the branch (sterile portion), ca. 1–3 (–12) mm, flattened at base, ascending or appressed to the main axis, ca. 6–30 flowers on primary branches; secondary branches 1–1.5 cm long, with ca. 4–10 flowers each; floral bracts transversely oblong to wide elliptic, short acuminate, 8.7–9.4 mm long, 5.8–6 mm wide, brownish, margin erose, densely white lepidote, 7-nerved, exceeding sepals and petals; flowers densely clustered and covered by a dense white indumentums which is cotton like and becomes brownish with age, 7–7.5 mm long, 4–4.6 mm diameter, sessile; sepals connate by ½ of their length, ovate, acute, 6.2–6.5 mm long, 4–4.2 mm wide, brownish, margin erose, densely white lepidote, 5-nerved, carinate, sometimes as long as the petals; petals free, ovate, acute, 6.5–6.9 mm long, 3.8–4.4 mm wide, white, entire, densely white lepidote, 7-nerved; staminodes narrowly triangular, 2.6–3.8 mm long, 0.5–0.7 mm wide at base; vestigial anthers triangular; filaments adnate to the base of petals and ovary, white; ovary superior, ovoid, 6 mm long, 3 mm diameter, white or greenish; stigmatic lobes erect, ca. 1.5–1.8 mm long; placentation central, ovules ovoid, covered by a membranous, transparent wing, 0.8 mm long, 0.6 mm de diameter including the wing. Fruits ellipsoid to wide ellipsoid, 7.2–8 mm long, 4–5.2 mm wide, brown, sepals, petals, staminodes, and stigmatic lobes persistent remaining on the fruit; seeds fusiform, 3.3–3.9 mm long, 1–1.4 mm wide, brown with two apical wings; apical wing 0.3–0.5 mm long, basal wing 0.4–0.9 mm long.

Distribution and habitat:— Hechtia hernandez-sandovalii has been so far only collected in a very restricted area in the extreme southwestern portion of Tamaulipas, Municipio Miquihuana, at the localities of La Peña, Estanque de Los Walle, Estanque Eguia, Servando Canales, La Perdida, San José del Llano, and Miquihuana (figure 4). The new species is an important component of what has been denominated “rosetofilous acaulescent thickets of Hechtia ” (Treviño-Carreón & Valiente-Banuet, 2005), on extensive limestone hills or rocky exposed areas. Also but less often, the new species can be found inhabiting the lower stratum of pine forest and rosetofilous caulescent thickets of Dasylirion miquihuanense Bogler (1998: 76) and D. qudrangulatum S. Watson (1879: 250) . In the plains and plateaus of these same sites, Hechtia hernandezsandovalii is often found associated with Agave lechuguilla Torrey (1858: 213) forming a plant association called “ Agave - Hechtia acaulescent rosetofilous shrubland”. Rosetofilous shrublands are interspaced with rosetofilous forests of Yucca filifera Chabaud (1876: 432) and Y. carnerosana ( Trelease 1902: 118) McKelvey (1938: 24) , as well as microphilous shrublands of Larrea tridentata ( Candolle 1824:706) Coville (1893: 75) . The distribution area is located between 1800 to 2200 m above sea level, with rains during summer (July to September) ranging from 500 to 700 mm, with temperatures ranging from -4°C and 41°C. The new species blooms from May to June, producing fruits in the following three months, which remain on the plant for a year when they open and free the seeds.

Other species usually found growing with Hechtia hernandez-sandovalii are Agave striata Zucc. ( Karwinsky & Zuccarini, 1833: 678), Celtis pallida Torrey (1859: 250) , Cylindropuntia leptocaulis ( Candolle 1828b: 118) F.M. Knuth ( Backeberg & Knuth 1935:122), Euphorbia antisiphylitica Zuccarini (1832: 292) , Jatropha dioica Sessé in Cervantes (1794: 4), Koeberlinia spinosa Zuccarini (1832: 359) , Lippia graveolens Kunth (1817 “1818“: 266), Opuntia imbricata ( Haworth 1819: 70) Candolle (1828a: 278) , Opuntia stenopetala Engelmann (1856: 289) , Pinus cembroides Zuccarini (1832: 392) , Pinus nelsonii Shaw (1904: 122) , Prosopis glandulosa Torrey (1827: 192) , among others.

Additional specimens examined (paratypes): — MEXICO. Tamaulipas: Mun. Palmillas, 8.5 al noroeste de Palmillas [23°22’06’’N, 99°30’53’’O], 1550 m snm, 7 Julio 1985, P. Hiriart, V. Juárez y R. Molczadzki 937

fruits ( MEXU!, UAT!); 926 ♀ ( MEXU!); Mun. Miquihuana , 1 km delante de la Perdida, [23°33’18’’N, 99°51’58’’O], 1850 m snm, 4 Junio 1986, H . Sánchez-Mejorada 3648 ♀ ( MEXU! (2)); 17 km al O de Miquihuana camino a Estanque de Los Walle , 23°62' N, 99°06' W, 28 Mayo 1986, L . Hernández & M . Martínez 1799 ♂ ( MEXU! (2), TEX-LL!, UAT!); 1.5 km después de la desviación hacia Estanque Los Walle , 23°32’41’’N, 99°53’53’’O, 1461 m snm, 12 Julio 2012, C . Jiménez, J . Treviño, A . de León, O . López y T . Hernández 27 ♀ ( CICY!, IEB!, US!), C . Jiménez, J . Treviño, A . de León, O . López y T . Hernández 27a ♂ ( CICY!, HGOM!, IEB!, US!, XAL!); 5.5 km al O de Miquihuana, por la carretera a San José del Llano , 2 km antes del entronque de la Perdida, 23°32’34.3’’N, 99°50’31.5’’W, 1592 m, 12 Junio 2009, I . Ramírez, J . Treviño & S . Terán Treviño 1610 ♂ ( CICY!); 1610a fruits ( CICY!) .

Etymology: —We dedicate this species to Luis G. Hernández Sandoval who collected the type material of this new species.

Discussion: —The new species along with additional ca. 10 taxa, are part of a group defined as the Hechtia glomerata Zucc. complex by Jiménez (2011) who characterized it by the presence of lateral, paniculate inflorescences, 1–3 divided, peduncle flattened at its base, a white indumentum covering all the inflorescences and its parts in both staminate and pistillate plants. Flowers on species on this complex are generally grouped in glomerules or sometimes laxly disposed along the branches, sessile to subsessile, pistillate and staminate flowers with white petals, those staminate with white filaments, green to yellowgreenish anthers, those pistillate with white stigma, and fruits with fusiform seeds. Phylogenetic analysis are on their way but preliminary results with morphological characters and sequences of the plastid region rpl 32 for 38 taxa of Hechtia suggest the monophyly of the complex (I. Ramírez et al., unpublished).

The new species resembles Hechtia glomerata Zucc. , a species also characterized by the presence of lateral inflorescences, but with rosettes producing stolons, leaves horizontally extended with deflexed apices, producing open rosettes that are wider than tall, foliar laminae with adaxial surface shiny and usually coloring red. Its pistillate branches are condensed, glomerule like, but staminate branches are elongated, and both of them covered by a thin layer of white indumentums and flowers present white petals. On the other hand, rosettes of Hechtia hernandez-sandovalii do not produce stolons, their leaves are erect, falcate, producing rosettes that are taller than wide, with foliar laminae green without developing red color. Its pistillate as well as staminate branches are cylindrical and these covered by a dense white indumentums which is cotton like and becomes brownish with age.

A more detailed study of floral features shows that foliar sheaths on the new taxon are shorter (2.5–3 cm vs. 3–6 cm in H. glomerata ), its floral parts larger (floral bracts, petals, sepals, ovary, anthers, and staminodes), as well as larger fruits but contrastingly smaller seeds in H. hernandez-sandovalii . Growth habit also differs between these species: H. hernandez-sandovalii form circular colonies of tens of rosettes. New ones are produced on the periphery with central, old ones gradually dying (and becoming black when eventually burned), making the colony acquire the aspect of a "fairy ring". On the other hand, rosettes of H. glomerata form small colonies of few rosettes, usually developing stolons, but never forming a circular colony on a shape of a fairy ring, with and all rosettes remaining alive.

The indumentum density in the new taxon varies from populations at high elevations (ca. 1800 m, e.j. locality La Peña) to slighter thinner at elevations below 1800 m. We have under cultivation representatives of several populations of Hechtia glomerata spanning the altitudinal range of the species and the indumentum density in the inflorescences is not affected by changes of elevation brought about by this common garden experiment, thus supporting the notion that this character is not affected by elevation differences within the species.

IUCN Conservation assessment:—IUCN Conservation assessment: —VU. Hechtia hernandezsandovalii meets criteria D2 of the IUCN (2001). The species is known from an area of less than 2 km 2 within which it occurs only at a handful of small sites. Albeit local populations of the species can be rich in individuals and are often inaccessible, they are widely dispersed and isolated on the slopes and tops of small hills.

MER Conservation assessment:—MER Conservation assessment: —A (“Amenazada”, “threatened”). Hechtia hernandez-sandovalii is known from an area of smaller that 0.2% of the Mexican territory. After assessing all the criteria of this method, and based upon the relevant factors established in the preceding paragraphs, H. hernandez-sandovalii scores 12 points, which places it in the mentioned category (SEMARNAT, 2002).

Figures

FIGURE 1. Hechtia hernandez-sandovalii (A, C, E, F). A. Plant in habit. C. Young staminate inflorescence showing white indumentum. E. Staminate branch. F. Pistillate branch. Hechtia glomerata (B, D). B. Plant in habit, see rosette shape and leaf color. D. Staminate (above) and pistillate (below) flowers. Photographs A, B, C, D by Ivón Ramirez; E and F by Jacinto Treviño Carreón.