Tillandsia usneoides

Rossado, Andrés J., Donadío, Sabina & Bonifacino, José M., 2024, A taxonomic revision of Tillandsia (Tillandsioideae, Bromeliaceae) from Uruguay, Phytotaxa 667 (1), pp. 1-90 : 1-90

16. Tillandsia usneoides (L.) Linnaeus (1762: 411). Figs. 16F , 42 , and 43.

≡ Renealmia usneoides Linnaeus (1753: 287) . Type (lectotype designated by Gouda 1987: 68):—Without locality: Hortus Cliffortianus, s.d., s.leg. in Clifford herbarium p. 129, Renealmia 1 (BM000558543 [online image!]).

Plants very long-caulescent, branched, forming hanging and dense clumps. Roots absent in adult plants. Stems up to 2 m long, pendant. Leaves distichously arranged, laxly distributed along the stem, grayish; sheaths 5–9 × ca. 2–3 mm, distinct from the blade, narrowly elliptic-oblong, densely lepidote; blades 20–40(–60) × ca. 0.5 mm, mostly spreading, linear, not channelled, fleshy, densely lepidote, trichomes asymmetric. Inflorescences 1-flowered; peduncles basally hidden by the terminal leaf sheath then exposed, 0.9–2 mm long, with trichomes all along except the glabrous hidden basal portion; peduncle bracts 2 in number, erect, apically clustered; upper peduncle bract with developed blade; sheath 3–4 × ca. 3 mm, widely elliptic, grayish-green to grayish-vinaceous, subdensely to densely lepidote except for the glabrous base; blade 5–30 mm long. Floral bracts generally with a short blade, ecarinate; sheath (2.5–)3–4 × 2.5– 4 mm, shorter than the sepals, clasping the base of the flower, widely elliptic to widely ovate, greenish to vinaceous, with trichomes clustered apically and sometimes also with scattered trichomes in the middle portion; blade 0.3–3 mm long. Flowers 7–9 mm long, weakly fragrant; sepals visible, 4.4–6.5 × 1.5–2 mm, evenly connate at the base for 1–2.5 mm, narrowly elliptic, ecarinate, greenish to vinaceous, glabrous or sometimes with scattered trichomes; petals 6.5–8.5 × 1.3–2 mm, lingulate; distal portion greenish-yellow, divergent to spreading, margins entire; stamens 3.7–4.7 mm long, deeply included, longer than the pistil; filaments 2.6–3.5 mm long, straight (not plicate); pollen yellow; pistil 2.4–3.5 mm long, deeply included; ovary 1.1–1.6 × ca. 1 mm, obovoid-prismatic, abruptly contracted into the style; style 0.8–1.4 mm long, about as long as the ovary, whitish; stigmas simple-truncate. Capsules not seen.

Vernacular names:— Barba del monte ( Herter 1949 –1956; Brito & Llano 2008), barba del palo ( Herter 1949 – 1956), barba de Tala ( Herter 1949 –1956; Brito & Llano 2008; Osten 3121 [MVM]), barba de viejo ( Herter 1949 –1956; Brito & Llano 2008), musgo blanco ( Herter 1949 –1956).

Classification:— Tillandsia usneoides belongs to T. subg. Diaphoranthema ( Smith & Downs 1977; Donadío et al. 2015, 2022).

Distribution and habitat:— Tillandsia usneoides is the most extensively distributed species within the Bromeliaceae family, occurring from the southeastern United States to central Argentina and central Chile (38º N – 39º S but mostly absent in the Amazonian region).

In Uruguay, Tillandsia usneoides is widely distributed, likely absent only in central-southern Uruguay (the gatherings of this species in Montevideo are recent and limited to anthropized areas, leading us to consider T. usneoides to be probably not native to this department; Fig. 43 ). Despite its wide distribution, Tillandsia usneoides has been poorly sampled, what could explain the lack of records in some large areas of Uruguay. However, based on our own fieldwork and the information from herbarium specimens, this species appears to be more frequent in eastern and northeastern Uruguay, where higher humidity conditions prevail.

Tillandsia usneoides in Uruguay is exclusively found as epiphyte in a variety of habitats (riverside forest, moist hillside forest, and psammophilous forest), where it grows hanging from branchlets, mainly in partly shaded conditions. Despite being a common species, its distribution is not continuous within its range, and its density varies significantly among sites within the same woodland. In this sense, some sites support large populations, while in others, the species is rare or entirely absent. This pattern may be attributed to the highly effective vegetative propagation of this species.

Phenology:— Flowering from late November to mid-January (late spring–early summer), with peak flowering in December ( Fig. 4 ). In Uruguay, although it is common to find plants of Tillandsia usneoides in flower, it is very rare to find them with fruits. Furthermore, it was not possible to obtain fruits in cultivated plants; therefore, we could not assess the timing of fruiting or fruit dehiscence.

Conservation:— We consider Tillandsia usneoides as Not Threatened in Uruguay. This species is common and widely distributed.

Diagnostic characters:— Tillandsia usneoides has a highly distinctive general appearance (much-branched clumps, with long, thin, and pendant stems), not having morphologically similar species within Uruguay. Additionally, T. usneoides is the only species in the country with visible stems; in all the other species the leaves are always imbricate.

Background in Uruguay:— Tillandsia usneoides was first cited for the Uruguayan flora by André in 1905, without specifying any reference material. A herbarium specimen of this species from Uruguay was first mentioned by Herter in 1930.

Representative specimens examined:— URUGUAY. Artigas: Río Cuareim y Arroyo Catalán Grande , 5 May 1979, Ziliani s.n. ( MVFA 16218 ) . Cerro Largo: Arroyo de la Mina , 24 February 2013, Rossado & Mai 129 ( MVFA) .

Durazno: Lago Rincón del Bonete , costa del Río Negro, entre brazo del Sauce y Brazo del Sarandí , 12 March 2014, Haretche 720 ( MVFA) . Florida: Estancia Santa Clara, Arroyo Timote , 6 January 1937, Rosengurtt B-2393 ( BA, MVFA) . Lavalleja: Arroyo Gutierrez y Ruta 8, 20 February 2013, Rossado et al. 88. ( MVFA) . Maldonado: Gruta de Salamanca , 26 November 2012, Rossado & Mai 64 ( MVFA) . Montevideo: Jardín Botánico de Montevideo, March 2018, Rossado 503 ( MVFA) . Rio Negro: Estancia Las Lilas , 25 June 2013, Haretche 590 ( MVFA) . Rivera: Balneario El Ceibal (Arroyo Coronilla chico y Ruta 6), 20 November 2015, Rossado 427 ( MVFA) . Rocha: Balneario Saglia, Laguna Merín , 21 October 2012, Brussa & Gago 4936 ( MVJB) . Salto: Salto Grande , 3 February 1966, Del Puerto & Marchesi s.n. ( MVFA 5903 ) . Soriano: Arroyo Grande, paso Piedras, Mercedes , 21 December 1894, Osten 3121 ( MVM) . Tacuarembó: Gruta de los Helechos , 25 November 2011, Mai & Rossado s.n. ( MVJB 28090 ) . Treinta y Tres: Quebrada de los Cuervos , 6 December 2014, Rossado et al. 406 ( MVFA) .

Figures

FIGURE 4. Phenology of Tillandsia species occurring in Uruguay. Divisions within each month indicate intervals of approximately 10 days, identified as the beginning, middle, and end of each month. Tillandsia loliacea is excluded due to lack of enough information. * Denotes species with cleistogamous flowers. ** Denotes species with insufficient data to ascertain the timing of fruiting or fruit dehiscence.

FIGURE 16. Illustrations of floral parts. A. Tillandsia capillaris. B. T. loliacea. C. T. virescens. D. T. tricholepis. E. T. recurvata. F. T. usneoides. From left to right: floral bract (stretched view), sepals (stretched view; adaxial sepals to the right), petal (stretched view), and pistil.A based on Rossado 404 (MVFA); B based on Villagrán et al. s.n. (MVJB 30693); C based on Rossado 362 (MVFA); D based on Rossado 363 (MVFA); E based on Rossado 415 (MVFA); F based on Rossado et al. 406 (MVFA).

FIGURE 42. Tillandsia usneoides. A. Habitat; moist hillside forest in Quebrada de La Teja (Treinta y Tres, Uruguay). B. Habit (Arroyo Yerbal Chico, Treinta y Tres, Uruguay). C. Detail of a flowering plant (Quebrada de Los Cuervos, Treinta y Tres, Uruguay). D. Close up of a shoot bearing a flower. E. Lateral view of the flower. F. Open capsule. Photos by Andrés Rossado.

FIGURE 43. Distribution map of Tillandsia usneoides in Uruguay and neighboring areas.