Tradescantia valida G. Brueckn ., Notizbl. Bot. Gart. Berlin-Dahlem 11: 510. 1932.

Pellegrini, Marco O. O., Forzza, Rafaela C. & Sakuragui, Cassia M., 2017, Novelties in Brazilian Tradescantia L. (Commelinaceae), PhytoKeys 80, pp. 1-31 : 7

Tradescantia valida G. Brueckn., Notizbl. Bot. Gart. Berlin-Dahlem 11: 510. 1932. Figs 3 , 8

Type.

BRAZIL. cult. in Hort. Bot. Münster /W., fl., fr., 28 Apr 1932, s.leg. s.n. (holotype: B barcode B 100296487!) .

Description.

Herbs ca. 30-70 cm tall, with indefinite base, rupicolous, rarely terrestrial. Roots thin, fibrous, cream to light brown, emerging from the nodes touching the substrate. Stems erect, succulent, little branched only at the base; internodes 1.8-7 cm long at base, distally shorter, green, sometimes with vertical reddish purple striations, glabrous. Leaves spirally-alternate, sessile; sheaths 0.4-1.8 cm long, light green, sometimes with vertical green or reddish purple striations, glabrous, margin setose, with long hyaline hairs; blades linear elliptic to linear lanceolate to lanceolate, rarely ovate, 2.7-18.2 × 1.1-2.5 cm, falcate to complicate, succulent, glabrous, adaxially light to medium green, abaxially light green, rarely tinted vinaceous to completely vinaceous, turning olive-green to light brown when dry, base truncate to obtuse, margin green to vinaceous, setose at base or until the middle with long hyaline hairs, slightly revolute, apex acute to acuminate; midvein conspicuous to inconspicuous, secondary veins inconspicuous, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 3.5-52 cm long, green, glabrous; basal bract inconspicuous, tubular, hyaline, glabrous; peduncle bracts absent; supernumerary bracts present, 1-3 per inflorescence, similar in shape and size to the cincinni bracts; cincinni bracts unequal among themselves, lanceolate to ovate, rarely broadly ovate, 1-3.5 × 0.3-1.2 cm, spathaceous, glabrous, light-green, abaxially slightly lighter, base truncate to obtuse, not saccate, margin green, setose at base or until the middle with long hyaline hairs, apex acute; double-cincinni (4-)6-26-flowered; bracteoles inconspicuous, imbricate, linear-triangular to triangular, hyaline. Flowers bisexual, actinomorphic, flat (not forming a floral tube), 1-1.5 cm diam.; floral buds broadly ellipsoid, apex acuminate; pedicels upright at anthesis and pre-anthesis, reflexed at post-anthesis, 0.7-2 cm long, green, glabrous, rarely sparsely glandular-pubescent, if present hairs hyaline; sepals 3, equal, free, ovate, cucullate, margin hyaline, apex acute, persistent in fruit, 4.8-7.3 × 1.5-3 mm, green, without dorsal keels, glabrous, rarely sparsely pilose at the apex, hairs eglandular, hyaline; petals 3, equal, free, elliptic to ovate, rarely broadly ovate, not clawed (sessile), flat, 5.2-8.6 × 2.7-5.4 mm, white to white with pink apex to light pink; stamens 6, arranged in two series, equal, filaments free from the petals and from each other, filaments 2.8-5 mm long, straight at anthesis and post-anthesis, basally densely bearded with moniliform hairs, hairs as long as the stamens, white, anthers basifixed, rimose, 0.8-1 × 1-1.2 mm, connective expanded, rhomboid, yellow, anther sacs ellipsoid, divergent, yellow, pollen yellow; ovary sessile, subglobose to globose, 1-1.7 × 1-1.3 cm, white, smooth, glabrous, 3-loculate, locules equal, locule 2-ovulate, ovule uniseriate, style straight, white, cylindrical, conical at the apex, 4-5.8 cm long, stigma punctate, pistil longer than the stamens. Capsules subglobose to broadly oblongoid, 2.8-4.2 × 1.8-3 mm, light to medium brown when mature, smooth, glabrous, loculicidal, 3-valved, sometimes apiculate due to persistent style base. Seeds exarillate, 1-2 per locule, 1.4-3 × 1-1.8 mm, ellipsoid to trigonal, cleft towards the embryotega, ventrally flattened, testa grey to greyish brown, farinose, costate arranged in ridges radiating from the embryotega; embryotega dorsal, relatively inconspicuous, generally covered by a cream farina, without a prominent apicule; hilum linear, longer than ½ the length of the seed.

Specimens seen.

BRAZIL. Rio Grande do Sul: Jaguari, ca. 12.5 km ao norte de Jaguari na BR-287 em direção a Santiago, fl., fr., Dec 2005, L.Y.S. Aona & M.C. Machado 958 (UEC 3ex); loc. cit., gruta linha 1, fl., fr., 27 Dec 1985, J.N.C. Marchiori 149 (HDCF).

Distribution and habitat.

Tradescantia valida is endemic to Brazil, more precisely to the state of Rio Grande do Sul (Fig. 8 ). It can be found growing as rupicolous, rarely as a terrestrial, in rocky walls.

Phenology.

It was found in bloom and fruit in December and April.

Conservation status.

Tradescantia valida is only known from the cultivated type collection and collections in Jaguari, state of Rio Grande do Sul. Thus, in accordance with the IUCN recommendations ( IUCN 2001), it should be considered as Data Deficient (DD), until further information on the species becomes available.

Discussion.

Tradescantia valida is closely related to the remaining three species in the T. crassula group, due to its erect habit, definite base, sessile, conduplicate to falcate, succulent leaves, generally with inconspicuous secondary veins, cincinni bracts non-saccate at base, pistil longer than the stamens, hilum longer than ½ the length of the seed, and for preferentially inhabiting open areas and rocky outcrops ( Pellegrini 2015, 2016). Tradescantia valida can be differentiated easily from all remaining species of the T. crassula group by its spathaceous cincinni bracts and by the presence of supernumerary bracts. The presence of spathaceous cincinni bracts is a character previously reported in T. sect. Austrotradescentia exclusively for T. umbraculifera Hand.-Mazz., a member of a clade named T. fluminensis group by Pellegrini (2015), and thus quite remarkable in this distantly related species. Aside from that, the presence of supernumerary bracts is unique within T. sect. Austrotradescantia , but well-known in species from T. sect. Cymbispatha ( Pellegrini 2015; Pellegrini et al. 2016) and T. sect. Mandonia ( Grant 2000; Pellegrini 2015).

In the T. crassula group, T. valida is similar to T. cerinthoides due to its sepals without dorsal keels. However, they can be easily differentiated due to its generally linear elliptic to linear lanceolate to lanceolate leaf-blades (vs. elliptic to broadly elliptic or ovate to broadly ovate or obovate to broadly obovate, in T. cerinthoides ), glabrous with margins setose at the base or until the middle (vs. pubescent on both sides or only abaxially, rarely glabrous on both sides with ciliate margins), and pedicels and sepals glabrous or only sparsely pubescent with eglandular hairs (vs. evenly densely velutine to hispid, sometimes with a mixture of glandular and eglandular hairs). Tradescantia valida is much more similar to T. crassula and T. seubertiana M.Pell., due to their leaf-blades and floral pubescence. These species can be easily differentiated by the pubescence of the margin of their leaf-sheaths (ciliate to shortly-setose in T. crassula ; glabrous in T. seubertiana ; and long-setose in T. valida ), the pubescence of their sepals (long-setose along the keels in T. crassula ; glabrous in T. seubertiana ; and glabrous or with few hairs at the apex in T. valida ), and by the shape of their floral buds (broadly ovoid T. crassula ; ellipsoid in T. seubertiana ; and ellipsoid in T. valida ).

Figures

Figure 3. Tradescantia valida G. Brueckn. Holotype of T. valida (B barcode B 100296487). Photograph courtesy of the Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universitaet Berlin.

Figure 8. Distribution map of studied Tradescantia L. in the South American domains. Full squares - T. crassula; White squares - T. chrysophylla; Triangles - T. valida; Circles - T. ambigua; Stars - T. boliviana. Light green- Amazon Forest; Orange- Cerrado; Red- Caatinga; Yellow- Chaco and Pantanal; Olive-green- Pampa; Dark green- Atlantic Forest; Purple- Andean Yungas.