Tillandsia uruguayensis Rossado, 2018

Rossado, Andrés J., Donadío, Sabina & Bonifacino, José M., 2018, Tillandsia uruguayensis (Tillandsioideae, Bromeliaceae), a new epilithic species from Uruguay, Phytotaxa 345 (2), pp. 133-142 : 134-141

Tillandsia uruguayensis Rossado , sp. nov. ( Figs. 1–2 )

Tillandsia uruguayensis is morphologically very close to T. lorentziana but differs from the latter by its longer basal floral bracts (26–45(– 51) mm vs. 19–28(–32) mm long), sepals from the basal flowers reaching less than 3 / 4 of the length of its respective floral bract (vs. more than 3 / 4

), spatulate petals (vs. lingulate), and straight filaments (vs. plicate).

Type: — URUGUAY. Rivera: Cerro Batoví Dorado, paredones de arenisca endurecida, [31°4’19’’S, 55°25’42’’W], 30 August 2001 (fl.), C. Brussa s.n. (holotype MVFA 29683!).

Plant epilithic, short to long caulescent, branching strongly at the base and forming very dense clumps up to 60 cm in diameter. Roots up to 2.5 mm in diameter, present all along the stem, branched. Stems usually short but sometimes long (to 1 m long), then pendant for most of its length and apically ascending, old parts covered by remaining dry sheaths. Leaves spirally arranged, 9–19.5 cm long, 6 to 15 in number and clustered apically when the stem is developed; sheaths 1.6–4 × 1.5–3.1 cm, enfolding the stem, gradually merging into blades, fleshy and with membranaceous margins at the basal portion, white and greenish towards the blades, densely lepidote abaxially except for the glabrous very base, mostly glabrous adaxially except for the densely lepidote distal portion, trichomes appressed becoming tomentose towards the blades, margins with protruded larger trichomes at the distal portion; blades 5.5–16.5 × 0.7–1.8 cm, erect to divergent (seldom the older ones spreading), sometimes turning secund, very narrowly triangular, channeled except for the flat apex, fleshy, cinereous, densely tomentose-lepidote on both sides, margins with protruded larger trichomes at the base, trichomes asymmetric, apex narrowly acute. Inflorescences simple, 9–37 cm long (including the peduncle); peduncles elongate, slightly shorter to exceeding the leaves, wholly covered by bracts, (4.4–)5.5–22(–27.5) cm long, 1.8–3 mm in diameter, suberect to reflexed but mostly horizontal, straight or occasionally slightly curved, terete, greenish, glabrous; peduncle bracts 6–9(–13) in number, erect, clasping the peduncle, densely imbricate, at least twice as long as the internodes, the basal ones leaf-like, very densely lepidote, the upper ones bladeless, gradually resembling the floral bracts, (2.6–)3.1–5(–5.6) × 0.8–1.4 cm, narrowly elliptic-triangular to narrowly elliptic, chartaceous, grayishgreen or grayish-red, apex acute to obtuse, glabrous adaxially, sparsely lepidote to densely lepidote abaxially except for the usually glabrous base; fertile part of the inflorescence distichously and densely (2–)4–11(–16)-flowered, 4– 11(–15) cm long, 0.7–2 cm wide, straight, strongly complanate, narrowly elliptic, apex acute with one or few sterile bracts; rachis totally or partially hidden by the floral bracts, (1.3–)2–8.5(–12.7) cm long, stout, slight to distinctly flexuous, compressed, excavate next the flower, green, glabrous; floral bracts conspicuous, gradually reducing in size towards the apex, densely imbricate, 3–5 times longer than the internodes, suberect to erect, clasping the basal half of the flower, narrowly elliptic to narrowly triangular, ecarinate, prominently nerved, light green, yellowish-green, reddish or light pink, margins thin and nerveless, apex acute to obtuse, the basal floral bracts 26–45(–51) × 9.8–14 mm, exceeding the sepals by 9–22 mm, densely lepidote to glabrescent abaxially or less frequently glabrous, trichomes generally denser or concentrated towards the apex only, the upper floral bracts shorter, usually glabrous. Flowers 36– 57 mm long, suberect to erect, sessile, odorless; receptacle totally hidden by the floral bract, inconspicuous but stout, 0.6–3.2 mm long, green; sepals hidden by the floral bracts, 15–27 × 3.5–7.3 mm, erect, nearly straight, evenly very short connate at the base for less than 1 mm to free, narrowly elliptic to narrowly elliptic-ovate, sometimes narrowly elliptic-oblong, submembranaceous, prominently nerved, light pink to greenish, glabrous, margin thin and nerveless, apex acute, the abaxial sepal ecarinate, the adaxial sepals strongly carinate and usually longer and wider than the abaxial one; petals 36–57 mm long, free, spatulate, membranaceous, white; claws 3–4 mm wide, erect; limbs 5.7–10.5 mm wide, divergent to spreading, sometimes recurved towards the apex, elliptic, margins softly crenate, seldom entire, apex rounded or seldom obtuse; stamens 30–45 mm long, all equal in length, included but visible, equaling the petal claw; filaments 24–37 mm long, flat, flaccid, sublinear, gradually tapering distally, straight (not plicate), translucent; anthers 5–9 mm long, linear, subbasifixed, apically with a short connective extension; pistil 32–52 mm long, slightly exerted, exceeding the stamens; ovary 3.5–7 × 1.5–3.6 mm, ovoid, tapering into the style, light green; style 25–45 mm long, ca. 6–8 times as long as the ovary, white; stigmas simple-patent, whitish, lobes 1.3–2.8 mm long, linear, spreading, slightly recurved, densely papillate. Capsules 19–30 × 4–6 mm, totally or mostly covered by the sepals and not exceeding its respective floral bract, narrowly ellipsoid, erect, apex acute and up to 3.5 mm beaked.

Etymology: —The specific epithet refers to Uruguay, the country where the type specimen was collected.

Distribution and habitat:— Tillandsia uruguayensis is only known from northern Uruguay, in northern and northwestern Rivera and northern Tacuarembó ( Fig. 3 ), where it grows epilithical on vertical rocky surfaces at elevations of 150– 300 m. The habitat includes rocky cliffs alongside Lunarejo and Laureles rivers and their tributaries, the rocky walls of flat hills, and the rocky pillars of Tacuarembó ( Fig. 2A–B ). This xeromorphic species grows fully sun exposed, usually forming almost exclusive communities but sometimes associated with Dyckia sp. ( Bromeliaceae ) and several cacti species. Furthermore, T. uruguayensis occasionally grows as an epiphyte on trees close to the rocky surfaces where it is more abundant.

Additional sampling may further extend the distribution of Tillandsia uruguayensis , as there are other areas with suitable habitat for this species in northern Uruguay and southwestern Rio Grande do Sul, Brazil. However, despite having carried out an exhaustive search in several herbaria collections (mainly Brazilian herbaria cited above), we did not find any specimen supporting a wider distribution.

Ecology: — Tillandsia uruguayensis is a xeromorphic species due to its densely lepidote and gray-like leaf blades with conspicuous water storing tissue ( Barfuss et al. 2016). Furthermore, this species is categorized as an atmospheric Tillandsia as it is a non-tank plant that depends on almost exclusively absorptive leaf trichomes for water and nutrient uptake ( Benzing 2000).

Phenology:— Tillandsia uruguayensis flowers from late August to early November. Plants with unopened capsules were observed from October to April and seed dispersal from February to April. The flowering period lasts for 20 to 30 days in well-developed inflorescences. Generally, only one to two flowers are open at the same time per inflorescence. Each flower remains open for three to seven days.

Conservation assessment: — Tillandsia uruguayensis was categorized in the AOO analysis as Endangered (EN). This species is only known from about 10 scattered populations always associated with rocky walls or pillar formations of rare occurrence in the country. The rocky cliffs at the sources of Lunarejo and Laureles rivers, where some populations of this species are located, are well-preserved habitats mostly because of its difficult accessibility ( Fig. 2A–B ). Unfortunately the habitat at the flat hills of Rivera and the rocky pillars of Tacuarembó are threatened by Pinus plantations. Tillandsia uruguayensis has some of its populations protected as they occur in the conservation area ‘Paisaje protegido Valle del Lunarejo’. Nevertheless, conservation of the different localities where this species occurs is important not only due to its restricted distribution, but also because each population is unique in several morphological features (e.g. plant size, number of flowers per inflorescence, floral bracts color, size of flower and its parts, among others).

Taxonomic observations:— Tillandsia uruguayensis was collected for the first time in 1900 by José Arechavaleta in Tacuarembó ( Uruguay) without specifying the exact locality.This species was not collected again until 1984 and ever since then, several specimens have been herborized and identified only to generic level or as Tillandsia arequitae or T. xiphioides ( Brito & Llano 2008) ( Fig. 4A–D ). The last two species occur in Uruguay and despite being morphologically similar to T. uruguayensis , they both show clear differences with it. Tillandsia uruguayensis can be distinguished from T. arequitae by its erect to divergent and channeled leaf blades (vs. spreading to reflexed and flat at the base), odorless flowers (vs. fragrant), narrower petals limb (up to 10.5 mm vs. 11.5–17 mm wide), and sepals of the basal flowers reaching less than 3 / 4 of its respective floral bract (vs. ca. 3 / 4 or higher), among others characteristics ( Table 1). On the other hand, T. uruguayensis can be distinguished from T. xiphioides by its odorless flowers (vs. strongly fragrant), shorter sepals (1.5–2.7 cm vs. 3.2–5.2 cm long), smaller petals (less than 6 cm vs. at least 8.5 cm long), and narrower petals limbs (up to 10.5 mm vs. at least 17 mm wide) ( Table 1).

Specimens of Tillandsia lorentziana Grisebach (1874: 271) with simple inflorescences are the ones that morphologically show the greatest likeness to T. uruguayensis ( Fig. 4E–F ). Tillandsia lorentziana is a widely distributed species that occurs in Argentina, Brazil, Bolivia, and Paraguay and although it has not yet been registered for Uruguay it has been collected in Rio Grande do Sul ( Brazil) in an area very close to the border with Uruguay. Tillandsia uruguayensis differs from T. lorentziana by its channeled leaf blades (vs. flat at the base), sepals of the basal flowers reaching less than 3 / 4 of its respective floral bract (vs. more than 3 / 4), spatulate petals (vs. lingulate), and straight filaments (vs. plicate) ( Table 1).

Additionally, Tillandsia uruguayensis shows morphological similarities with Tillandsia afonsoana Strehl (2000: 23) , T. barfussii W. Till (2009: 36) , T. cardenasii L. B. Smith (1935: 154) , and T. chiletensis Rauh (1984: 5) . Tillandsia afonsoana is an endemic species from Rio Grande do Sul ( Brazil) morphologically similar to T. lorentziana . Tillandsia uruguayensis can be easily distinguished from T. afonsoana because its floral bracts exceed its respective sepals by at least 9 mm (vs. equal in length to the sepals or exceed them by at most 6 mm), it has straight filaments (vs. plicate), and floral bracts 9.8–14 mm wide (vs. 8.0– 10 mm). Likewise, Tillandsia uruguayensis differs from Tillandsia cardenasii , an endemic species from Bolivia, by its longer basal floral bracts (26–51 mm vs at most 27 mm long), sepals from the basal flowers reaching less than ¾ of the length of its respective floral bract (vs. barely shorter), petals spatulate, white, 5.7–10.5 mm wide (vs. lingulate, lilac, 2–3 mm wide), and straight filaments (vs. plicate). Tillandsia barfussii and T. chiletensis show morphological similarities with T. uruguayensis , especially regarding reproductive structures. Tillandsia uruguayensis can be distinguished from both species by its longer floral bracts (26–51 mm vs. T. barfussii : 19–21 mm, T. chiletensis : ca. 25 mm long), sepals much shorter to its respective floral bracts (vs. equal or subequal), and outer leaf blades channeled (vs. flat at least at the base). In addition, T. uruguayensis has densely lepidote leaf sheaths (vs. T. chiletensis : glabrous sheaths), floral bracts 9.8–14 mm wide (vs. T. chiletensis : ca. 6 mm), and straight filaments (vs. T. barfussii : plicate).

It should be noted that Tillandsia lorentziana f. simplex Kuntze (1898: 304) , currently considered a synonym of T. lorentziana , was differentiated in the original publication from the typical form by the presence of simple inflorescences instead of compound ones. Given that T. uruguayensis is morphologically similar to plants of T. lorentziana with simple inflorescences, we analyzed the type material and the protologue of T. lorentziana f. simplex and concluded that this form has no other differences with the typical form except for the inflorescence type. Thus, we reject the possibility that material here recognized under T. uruguayensis correspond to T. lorentziana f. simplex .

Additional specimens examined (Paratypes):— URUGUAY. Rivera: Arroyo Gajo del Lunarejo , 31°09’4.0’’S, 55°59’31.6’’W, 22 April 2011 (cultivated in Montevideo, pressed 16 October 2016), Rossado 462 (MVFA!) ; Arroyo Lunarejo , [31°09’S, 55°59’W], 15 February 1996, Grela & Romero s.n. (MVFA 26328!) ; Cerro Batoví Dorado , [31°04’19’’S, 55°25’42’’W], 12 January 2001, Brussa & Grela s.n. (MVFA 29515!) ; Cerro Batoví Dorado , 31°04’19.5’’S, 55°25’42.2’’W, 10 October 2015, Rossado & Bonifacino 418 (MVFA!, SI!, WU!) ; Cerro Chato Dorado , [31°03’59’’S, 55°27’27’’W], 12 December 1997, Marchesi & Grela s.n. (MVFA 27194!) ; Cerro Chato Dorado , [31°03’59’’S, 55°27’27’’W], 19 March 2001, Brussa & Grela s.n. (MVFA 29598!) ; Cerro Chato Dorado , 31º04’03’’S, 55°27’37.5’’W, 10 October 2015, Rossado & Bonifacino 420 (MVFA!) ; Cerro en Cuchilla de Cuñapirú , 31°00’45.7’’S, 55°35’55.5’’W, 10 October 2015, Rossado & Bonifacino 422 (MVFA!) . Tacuarembó: Arroyo Laureles , [31°15’S, 56°04’W], 15 May 1984, Majó et al. s.n. (MVJB 21383!) ; Arroyo Laureles , Salto grande, [31°14’26’’S, 56°04’44’’W], 29 September 2005, Brito & Llano s.n. (MVFQ 4355!) ; Cascada de las Bandurrias, Parao del cazador, Darío Fros , 12ª seccional, [31°17’56.6’’S, 56°01’34.3’’W], 12 July 2006, Brito & Llano s.n. (MVFQ 4356!) ; Cascada de Sonia, Cuchilla de Laureles , [31°19’16’’S, 55°’58’47’’W], 16 November 2003, Bonifacino 950 (MVFA!) ; Cascada de Sonia , 31°19’16.1’’S, 55°58’47.6’’W, 11 October 2015, Rossado & Bonifacino 423 (MVFA!) ; Gruta de los Cuervos , [31°37’20’’S, 56°02’36’’W], 12 May 1987, Delfino et al. s.n. (MVJB 23322!) ; Gruta de los Cuervos , 31°37’18.2’’S, 56°02’25.9’’W, 21 October 2005, Brussa s.n. (MVJB 23750!) ; Gruta de los Cuervos , 31°37’19.8’’S, 56°02’36.1’’W, 2 December 2013, Rossado et al. 338 (MVFA!) ; Gruta de los Cuervos , 31°37’19’’S, 56°02’36’’W, 3 November 2014, Rossado 440 (MVFA!) ; Pilares de Klinger , 31°36’37.9’’S, 56°04’45.3’’W, 11 October 2015, Rossado & Bonifacino 424 (SI!) ; Zapará , en el potrero 4 mirando al este, [31°37’02’’S, 56°03’36’’W], 1 October 2004, Brito & Llano s.n. (MVFQ 4357!) ; without exact locality, February, Arechavaleta 435 (MVM!); without exact locality, November 1900, Arechavaleta s.n. (MVM 2947!).

Figures

FIGURE 1. Illustration of Tillandsia uruguayensis from the type locality (Rossado & Bonifacino 418). A. Habit. B. Detail of the leaf blade trichomes; left: from the margin, right: from the surface of the blade. C. Cross-section of the leaf blade (from left to right): base, middle, apex. D. Cross-section of the peduncle, encircled by three peduncle bracts. E. Cross-section of the rachis. F. Abaxial face of an apical peduncle bract (stretched view). G. Abaxial face of a floral bract (stretched view). H. Diagram showing relative position of floral parts and associated structures: FB, floral bract; P, petal; Ra, rachis; Re, receptacle; S, sepal; SAL, sepal apparent length. I. Flower. J. Abaxial face of sepals (stretched view); left: adaxial sepal; right: abaxial sepal. K. Petal (stretched view). L. Stamen. M. Pistil. N. Stigma. Drawn by Andrés Rossado.

FIGURE 2. Tillandsia uruguayensis. A. General view of the habitat at the rocky cliffs of the Laureles river (Rivera). B. Population at the rocky cliffs of the Gajo del Lunarejo water course (Rivera). C. Habit of the plant pre-anthesis (Pilares de Klinger, Tacuarembó). D. Habit of a flowering plant at the type locality (Batoví Dorado hill, Rivera). E. Detail of the bases of the leaf blades; notice protruded larger trichomes along the margins. F.Inflorescences. G. Close up of the fertile part of the inflorescence. H. Front view of the flower. I. Capsule (floral bract and sepals removed). J. Infructescence. Photographs by Andrés Rossado.

FIGURE 3. Distribution map of Tillandsia uruguayensis.

FIGURE 4. Species morphologically similar to Tillandsia uruguayensis occurring in Uruguay and neighboring areas. A–B. T. arequitae (Arequita hill, Lavalleja, Uruguay). A. Habit. B. Inflorescence and flowers. C–D. T. xiphioides (San José, Uruguay). C. Habit. D. Inflorescence and flowers. E–F. T. lorentziana. E. Habit of a plant with simple inflorescences (Guasayán mountain range, Santiago del Estero, Argentina). F. Inflorescence (Jarau Hill, Rio Grande do Sul, Brazil). Photographs by Andrés Rossado (A–D), Sabina Donadío (E) and Fabiano da Silva Alves (F).