Tillandsia tricholepis Baker (1878: 237)

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

14. Tillandsia tricholepis Baker (1878: 237) . Figs. 16D , 38 , and 39.

Type (lectotype, first-step designated by Smith 1935: 191 [as “type”]):— BOLIVIA. La Paz: Larecaja , “Vicinüs Sorata; Poquerani, San Pedro, super frutices”, October 1858 – April 1859, Mandon 1179 p.p. (K [one sheet with admixtures], second-step lectotype designated here: K000321947 [online image!]; isolectotypes: BM000923944 [online image!], G00098166 [online image!], G00493947 [online image!], LE00006310 [online image!], MPU012478 [online image!], P00438696 [online image!], P00438697 [online image!], P00438698 [online image!], P01761330 [online image!], S-R-6158 [online image!], US00091125 [online image!], W0016726 [online image!], W-Rchb.1889-0262564 p.p. [online image!]) .

Plants long-caulescent, branched and forming dense moss-like clumps up to 15 cm in diameter. Roots up to 0.3 mm in diameter, mostly present at the base of the stem. Stems up to 15 cm long, suberect to pendant. Leaves spirally arranged, distributed along the stem, grayish-green; sheaths (2.7–) 3.3–4.2 mm wide, distinct from the blade, nearly orbicular, glabrous, sometimes with trichomes close to the blade; blades 4–9 × 0.9–1.8 mm, mainly suberect, narrowly triangular, adaxial face flat-convex to convex, fleshy, densely lepidote throughout, trichomes asymmetric. Inflorescences simple; peduncles mostly covered by bracts, 1–2 cm long, 0.4–0.6 mm in diameter, glabrous; peduncle bracts 2 to 3 in number, erect, evenly distributed along the peduncle, about as long as the internodes; upper peduncle bract bladeless, 5.5–8 × 3–3.6 mm, ovate to ovate-elliptic, grayish-green, subdensely lepidote. Spike distichously and densely (1)2 to 4(5)-flowered, 9–16 mm long, complanate, very narrowly elliptic in outline; rachis partially hidden by the floral bracts and flowers, green, glabrous. Floral bracts 3.8–7 × 3–4.2 mm, slightly shorter than the sepals, subdensely distributed (1.3–2.1 times longer than the internodes), not imbricate, clasping the basal half of the flower, bladeless, ovate to widely ovate, ecarinate, green to grayish-green (sometimes stramineous towards the apex), subdensely to densely lepidote. Flowers 7–9 mm long, scentless; sepals visible, 5–7 × 1.4–2 mm, evenly short connate at the base for 1–1.9 mm, narrowly elliptic, ecarinate, green, subdensely lepidote to sparsely lepidote in the apical half; petals 6.5–8 × 0.7–1.5 mm, lingulate, yellow; distal portion suberect to divergent, margins entire; stamens 3.3–4.3 mm long, deeply included, a little longer than the pistil; filaments 2.3–3 mm long, straight (not plicate); pollen yellow; pistil 1.8–2.9 mm long, deeply included; ovary 0.9–1.5 × 0.8–1.2 mm, obovoid-subprismatic, abruptly contracted into the style; style 0.8–1.3 mm long, about as long as the ovary, whitish; stigmas simple-truncate. Capsules (11–)13–20 × 0.7–1.1 mm, much exceeding its respective floral bract, cylindrical-prismatic, apex truncate and short-beaked.

Vernacular names:— Clavel musgo ( Brito & Llano 2008).

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

Distribution and habitat:— Bolivia, Paraguay, Brazil, Argentina, and Uruguay. Tillandsia tricholepis is widely distributed in both Brazil and Argentina. In Uruguay, this species occurs as native only in one location in north of the country (Artigas department; Fig. 39 ), where it exclusively grows as epiphyte in a transitional woodland between open thorn forests and riverside forests. This population occupies a small area (ca. 2 ha) but is represented by a high number of individuals, that grow on trunks and branchlets, in partly-shaded conditions, together with T. aëranthos , T. bandensis , T. loliacea , and T. recurvata . Additionally, this species is found as subspontaneous in Tacuarembó city and Salto city, where it grows as epiphyte on urban park trees.

Phenology: —In Uruguay, Tillandsia tricholepis flowers in late spring–early summer (December and January; Fig. 4 ). The fruits grow in February and March, and then remain without apparent growth for six to seven months until seed dispersal in spring (mainly in October and November). In each plant, a period of 13 to 14 months occurs between the onset of the inflorescence emergence and the dehiscence of its capsules (the development of the inflorescence takes approximately 60 to 80 days).

Reproductive observations:— According to Bianchi & Vesprini (2014), Tillandsia tricholepis is a self-compatible species. Cleistogamy has been reported for this species ( Bianchi & Vesprini 2014). In Uruguay, all the studied populations have chasmogamous flowers. Usually only one (occasionally two) flower is open at any given time per inflorescence, and it remains open from four to seven days.

Conservation:— We consider Tillandsia tricholepis as Threatened in Uruguay. So far, only one natural population of this species has been registered within the country, inhabiting a small patch of forest (approx. 2 ha) located in an area threatened by agricultural activities. Tillandsia tricholepis is not included as a priority for conservation in Uruguay by Marchesi et al. (2013), and is absent in national protected areas.

Diagnostic characters:— Tillandsia tricholepis is very easy to recognize due to the small size of its leaf blades (less than 10 mm long), the caulescent habit and the spiral phyllotaxis, which makes of this species the only Tillandsia in Uruguay that looks like a big moss or a small lycophyte.

Background in Uruguay:— Tillandsia tricholepis was first cited for the Uruguayan flora by Brito & Llano (2008) as a subspontaneous species in an urban park in Salto department.

Note:— Baker (1878) described Tillandsia tricholepis based on the single gathering Mandon 1179, but he did not specify the institution in which the type material was conserved. In this sense, several duplicates of Mandon 1179 were found in different herbaria (BM, G, K, LE, MPU, P, S, US, W), most of them identified by Walter Till, who has extensively studied Tillandsia subg. Diaphoranthema . After the detailed observation of the material of all the duplicates, and in agreement with the determination slips made by W. Till, we conclude that Mandon 1179 constitutes a mixed gathering. This observation was also made by Smith (1935) who stated “…the type of T. tricholepis came from a mixed number.” In this sense, eight herbarium sheets of Mandon 1179 have exclusively material of T. tricholepis (G00098166, G00493947, LE00006310, MPU012478, P00438696, P00438698, US 00091125, W0016726), while another six have admixtures. Of the latter, four have material of T. tricholepis and T. minutiflora Donadío (2011: 132) (BM, K, P, W), and two of T. tricholepis and T. virescens (P, S). Further, a complete herbarium sheet of Mandon 1179 ( US 01106048) holds exclusively material of T. minutiflora and therefore is discarded as type material of T. tricholepis .

Smith (1935) considered Mandon 1179 at K as “type” of T. tricholepis [then named as holotype in Smith & Downs (1977)], as it was clearly specified in his work “ Mandon 1179 e p [in part] (K, TYPE; BM, S, G, NY)”. By doing so, he 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 Mandon 1179 at K, it holds not only material from T. tricholepis (K000321947) but also, in much less proportion, of T. minutiflora (K001382263). Based on that, and in accordance with the ICN Art. 9.17, here we designate K000321947 as the second-step lectotype, as it is the part of the sheet of Mandon 1179 (K) which corresponds most nearly with the original description of T. tricholepis (ICN Art. 9.14; Turland et al. 2018).

Representative specimens examined:— URUGUAY. Artigas: Establecimiento RIUSA, 16 March 2013, Villagrán & Berazategui s.n. ( MVM 23003 ) . Salto: Ciudad de Salto - Parque Solari, s.d., Del Puerto & Ziliani s.n. ( MVFA 17390 ) . Tacuarembó: Plaza de la ciudad de Tacuarembó, 27 September 2009, Brussa 4649 ( MVJB) .

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 38. Tillandsia tricholepis. A. Plants in habitat (between the Uruguay River and Colonia Palma, Artigas, Uruguay). B. Plants growing on an urban tree (Tacuarembó city, Tacuarembó, Uruguay). C. Habit (between the Uruguay River and Colonia Palma). D. Front view of the flower. E. Close up of the fertile part of the inflorescence. F. Infructescence. Photos by Andrés Rossado.

FIGURE 39. Distribution map of Tillandsia tricholepis in Uruguay and neighboring areas. The collections from the departments of Salto and Tacuarembó (Uruguay) correspond to subspontaneous populations.