Tillandsia virescens Ruiz & Pavón (1802: 43)

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

17. Tillandsia virescens Ruiz & Pavón (1802: 43) . Figs. 16C , 44 , and 45.

≡ Diaphoranthema virescens (Ruiz & Pav.) Beer ([1856] 1857: 154) ≡ Tillandsia capillaris f. virescens (Ruiz & Pavón) L.B. Smith (1935: 212) . Type (lectotype designated here):— PERU. Huánuco: without exact locality, s.d., Ruiz & Pavón s.n. (MA810454 [online image!]).

= Tillandsia capillaris Ruiz & Pavón (1802: 42) f. cordobensis (Hieron.) L.B. Smith (1935: 211) ≡ Tillandsia cordobensis Hieronymus (1885: 10) . Type (lectotype first-step designated by Smith 1935: 211 [as “type”]):— ARGENTINA. Córdoba: Sierra de Córdoba, 1875–1876, Hieronymus 349 (B [one sheet with admixture], second-step lectotype designated here: B 10 1172573a [digital image!]; isolectotypes: CORD00002219 [online image!], GOET000433 [online image!]).

Plants caulescent, much branched from the base and forming very dense globose or semiglobose clumps up to 15 cm in diameter. Roots ca. 0.5 mm diameter, only present at the base of the stem. Stems up to 13 cm long. Leaves distichously arranged, distributed along the stem, grayish-green; sheaths 9–13 × 4.8–5.2 mm, distinct from the blade, elliptic, lepidote except for the glabrous base; blades (18–)23–46 × 0.8–1.3 mm, divergent to spreading, linear, not channelled, fleshy, densely lepidote, trichomes symmetric. Inflorescences 1-flowered (seldom 2-flowered); peduncles bractless (sometimes bearing a foliaceous basal bract), accrescent, 1.3–2.8 cm long when flowering, 3.5–8.5 cm long when fruiting, wholly glabrous or with the distal portion lepidote. Floral bracts with a short blade, seldom bladeless, ecarinate; sheath 4–9 × 4.5–6.5 mm, shorter than the sepals, clasping the base of the flower, widely ovate-elliptic, grayish-green, densely lepidote; blade to 6 mm long but generally much shorter. Flowers 8–11 mm long, fragrant; sepals visible, 6–8.5 × 1.4–2.3 mm, unequally connate, narrowly oblong to narrowly elliptic-oblong, ecarinate, vinaceous and generally with the apex and margins light yellow, sometimes the basal portion green, glabrous or sometimes with some scattered trichomes; abaxial sepal connate with the adaxial sepals for 0.8–1.4 mm; adaxial sepals connate to each other for 4.5–6.5 mm (more than ⅔ of their length); petals 8.2–11.3 × 1.4–2.1 mm, lingulate; distal portion yellow with vinaceous spots barely perceptible, spreading, margins entire; stamens 4.2–5.7 mm long, deeply included, longer than the pistil; filaments 3.2–4.1 mm long, straight (not plicate); pollen yellow-orangish; pistil 3–4.2 mm long, deeply included; ovary 1.5–2.5 × 1.1–1.6 mm, subprismatic, abruptly contracted into the style; style 1–1.5 mm long, a little shorter than the ovary, whitish-greenish; stigmas simple-truncate. Capsules 15–22 × 1.1–1.7 mm, much exceeding its respective floral bract, cylindrical-prismatic, apex truncate-obtuse and short-beaked.

Vernacular names:— Clavelito ( Brito & Llano 2008).

Classification:— Tillandsia virescens belongs to T. subg. Diaphoranthema , based on its morphological characteristics ( Smith & Downs 1977), and the morphological and molecular phylogenies by Donadío et al. (2015, 2022) and Granados Mendoza et al. (2017).

Distribution and habitat: — Tillandsia virescens is native to Peru, Bolivia, Chile, and Argentina. In Uruguay, however, it is considered an exotic species since it has never been documented in natural environments. Thus far, it has been observed growing exclusively in urban areas. The nearest natural populations of T. virescens are located more than 600 km from southern Uruguay, in the southern region of Buenos Aires province and the central region of Córdoba province, Argentina.

Within Uruguay, T. virescens is found exclusively in Montevideo city and its neighboring areas ( Fig. 45 ), where it is a common and widespread species. It typically grows as an epiphyte in urban parks, on street trees, and along power lines ( Fig. 44A ). Usually, it occurs associated with T. aëranthos , as well as morphologically similar species such as T. capillaris and T. recurvata , with which it is frequently confused.

Phenology: —In Uruguay, Tillandsia virescens flowers between mid-winter and early spring (August to October; Fig. 4 ). The fruits begin to develop as of September–October and remain unopened for 11 to 13 months until seed dispersal, which occurs from August to November (winter and spring) of the following year. Therefore, the opening of the capsules generated the previous year sometimes coincides with the flowering period of the present year, or may even occur after it. In the latter case, fruits generated the previous year are concurrent with the new fruits of the last flowering period.

As the development of the inflorescence takes between 60 and 80 days, the complete reproductive cycle (from inflorescence emergence to the dehiscence of its capsules) requires from 14 to 16 months to be completed.

Reproductive observations:— In the morphotype of T. virescens occurring in Uruguay (syn: T. cordobensis ), each plant remains with open flowers for approximately 30 to 45 days, and individual flowers remains open for 20 to almost 30 days. It should be noted that after the flowering period ends and during fruit maturation, the peduncles continue growing in length generally for several centimeters (accrescent peduncles; Fig. 44G ). In this sense, the peduncles are short and straight when the plants are flowering, and long and pendant once the fruits are ripe.

According to Till (1989a), Tillandsia virescens is a self-compatible species, with populations or individuals exhibiting both cleistogamous and chasmogamous flowers.In Uruguay, the observed plants always have chasmogamous flowers, which emit a sweet fragrance (similar to T. capillaris s.s.), particularly notable at dusk.

Conservation: —Not applicable. Tillandsia virescens is an exotic species to Uruguay.

Diagnostic characters:— In Uruguay, Tillandsia virescens can be differentiated from the other species of the genus by the combination of the following characters: distichous leaves, not channelled leaf blades (or, if channelled, then for less than ⅙ of the length), and lepidote floral bracts. However, this species is commonlY confused with T. capillaris and/or T. recurvata . In addition to the characters shown in the key, T. recurvata can be separated from the morphotype of T. virescens growing in UruguaY bY the presence of clearlY channelled leaf blades (at least for ⅕ of the length), or by the presence of trichomes throughout the peduncles (vs. only present in the peduncle apex). Both T. capillaris and/or T. recurvata have been found growing together with T. virescens .

Background in Uruguay:— The presence of T. virescens in Uruguay was first mentioned by Marchesi (1965) under the synonym Tillandsia cordobensis (with reference material). However, it should be noted that the name “ T. cordobensis ” had been previously cited by Herter (1949 –1956) but without referencing specimens. We consider this citation as an identification error, possibly with T. recurvata , as the illustration and location mentioned in Herter’s work do not match the morphological characteristics and distribution of T. virescens (syn: T. cordobensis ).

Note I: —The entity occurring in Uruguay and treated here as T. virescens corresponds to what Smith & Downs (1977) considered as Tillandsia capillaris f. cordobensis . In this work, we decide to follow the taxonomic proposal of Till (1989a) and Castello et al. (2016), in which the forms of T. capillaris s.l. were accommodated, based on morphological and molecular evidence, into two species: T. capillaris s.s. and T. virescens .

Note II: —In the protologue of Tillandsia cordobensis ( Hieronymus 1885) , more than one gathering is cited under the description of the species [“…habitat alt. 500–600 m s. m. in arboribus Polylepidis racemosae (Ruiz et Pav.), et aliis et in saxis praeruptis montium Sierra Achala et Sierra chica de Córdoba (coll. Hieronymus, n. 349 et sin. num.)…”]. Smith (1935) considered Hieronymus 349 at B as the “type” of T. cordobensis (under the name T. capillaris f. cordobensis ), and then it was cited as “ holotype ” in Smith & Downs (1977). In doing so, Smith (1935) made an inadvertent lectotypification ( Prado et al. 2015; ICN Art. 9.10, Turland et al. 2018). However, this can only be taken as the first step of a lectotypification since, despite the fact that there is only one sheet of Hieronymus 349 at B, it contains parts belonging to more than one taxon. In this sense, and in agreement with the determination slips made by W. Till, we consider that Hieronymus 349 at B holds material of T. cordobensis (accepted name T. virescens ) but also, in much less proportion, of T. capillaris (B 10 1172573b). Based on this, and in accordance with the ICN Art. 9.17, here we designate B 10 1172573a as the second-step lectotype, as it is the part of the sheet of Hieronymus 349 (B) which corresponds most closely with the original description and drawing of T. cordobensis (ICN Art. 9.14; Turland et al. 2018).

Note III:— Smith & Downs (1977) stated that the type of Tillandsia virescens is located at MA [“TYPE. Ruiz & Pavon s n (holotype MA n v, isotype F)]”. However, since they did not see the specimen at MA, it cannot be considered as an inadvertent lectotypification. Therefore, the lectotypification is performed in this work.

Representative specimens examined:— URUGUAY. Canelones: Parque Roosevelt , orilla sureste del lago, unos 150 m al NE de Av. De las Américas, 11 May 2009, Haretche 1305 ( MVJB) . Montevideo: Quinta de Santos - Instrucciones y Propios, 23 November 1963, Marchesi 780 ( 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 44. Tillandsia virescens.A. Plant growing on a power line in an urban area (Montevideo city, Montevideo, Uruguay). B. Habit (Montevideo city). C. Close up of an individual in bloom. D. Inflorescences. E. Front view of the flower. F. Lateral view of the flower with its floral bract. G. Close up of a reproductive shoot. Notice the difference in length between the flower-bearing and the fruit-bearing peduncles (acrescent peduncles). H. Capsule. Photos by Andrés Rossado.

FIGURE 45. Distribution map of Tillandsia virescens in Uruguay. All these populations are subspontaneous.