Tradescantia chrysophylla M.Pell., 2017

Pellegrini, Marco O. O., Forzza, Rafaela C. & Sakuragui, Cassia M., 2017, Novelties in Brazilian Tradescantia L. (Commelinaceae), PhytoKeys 80, pp. 1-31 : 4-6

Tradescantia chrysophylla M.Pell. sp. nov. Figs 2 , 8

Diagnosis.

Similar to T. cymbispatha due to its habit with an indefinite base, creeping stems with ascending apex, sessile succulent leaves with flat blades homogeneously covered by indumenta, inconspicuous secondary veins, saccate cincinni bracts, broadly ovoid floral buds, sepals without keels, and pistil the same length as the stamens. It can be differentiated by its velutine to hispid, golden to light brown indumentum covering almost the entire plant, strongly unequal cincinni bracts, and pedicels and sepals glandular-pubescent, or with a mixture of glandular and eglandular hairs.

Type.

BRAZIL. São Paulo: Biritiba Mirim, Estacao Biologica de Boraceia , fl., 24 Nov 1983, A. Custódio Filho 1910 (holotype: RB!; isotype: SP!) .

Description.

Herbs ca. 11-27 cm tall, with an indefinite base, terrestrial or rupicolous, rarely epiphyte. Roots thin, fibrous, cream to light brown, emerging from the nodes touching the substrate. Stems creeping to ascending at the apex, delicate to slightly succulent, densely branched; internodes 1.5-8.2 cm long at base, distally shorter, dark green to vinaceous, velutine to hispid, hairs golden to light brown. Leaves distichously-alternate, sessile; sheaths 0.4-1 cm long, green to vinaceous with dark green to purple striations, velutine to hispid, margin densely setose, hairs golden; blades broadly elliptic to broadly ovate, 1.8-7.6 × 0.9-3.4 cm, flat, succulent, velutine to hispid on both sides, hairs golden to light brown, adaxially dark green, abaxially vinaceous, turning dark brown to olive-green on both sides when dry, base cordate to rounded, margin ciliolate, apex acute, sometimes acuminate; midvein conspicuous, adaxially impressed, secondary veins inconspicuous, adaxially inconspicuous, abaxially inconspicuous, becoming more evident abaxially 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 (0.4-)1.1-9.5 cm long, vinaceous, velutine to hispid, hairs golden to light brown; basal bract inconspicuous, tubular, hyaline, glabrous; peduncle bracts absent; supernumerary bracts absent; cincinni bracts strongly unequal among themselves, elliptic to ovate to broadly ovate, 0.9-6.6 × 0.4-3.1 cm, leaf-like, velutine to hispid, hairs golden to light brown, adaxially dark green, abaxially vinaceous, base cordate to round, saccate, margin ciliolate, apex acute; double-cincinni (4-)6-12-flowered; bracteoles inconspicuous, imbricate, linear-triangular to triangular, hyaline. Flowers bisexual, actinomorphic, flat (not forming a floral tube), 1.1-1.6 cm diam.; floral buds broadly ovoid, apex acute; pedicels upright at anthesis and pre-anthesis, reflexed at post-anthesis, 0.9-1.3 cm long, glandular-pubescent, rarely with a mixture of glandular and eglandular, golden to light brown hairs; sepals 3, equal, free, ovate, cucullate, margin hyaline, apex acute, persistent in fruit, 4.7-5.8 × 2.6-4 mm, without dorsal keels, glandular-pubescent or with a mixture of glandular and eglandular, golden to light brown hairs; petals 3, equal, free, elliptic to ovate, rarely broadly ovate, not clawed (sessile), flat, 8.8-9 × 5.7-6.2 mm, white; stamens 6, arranged in two series, equal, filaments free from the petals and from each other, filaments 6-6.2 mm long, straight at anthesis and post-anthesis, basally densely bearded with moniliform hairs, hairs as long as the stamens, white, anthers basifixed, rimose, 0.6-0.8 × 0.3-0.7 mm, connective expanded, rhomboid, yellow, anther sacs ellipsoid, divergent, yellow, pollen yellow; ovary sessile, subglobose, 1.5-1.7 × 1.2-1.4 mm, white, smooth, glabrous, 3-loculate, locules equal, locule 2-ovulate, ovule uniseriate, style straight, white, cylindrical, conical at the apex, 4-4.2 cm long, stigma punctate, pistil the same length as the stamens. Capsules subglobose to globose, 2.7-3.2 × 2.2-2.8 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, 1.1-1.5 × 1.0-1.4 mm, ellipsoid to narrowly trigonal, not 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, ½ the length of the seed.

Specimens seen

(paratypes). BRAZIL. Paraná: Campo Largo, Caverna do Pinheirinho, fl., fr., 13 Oct 1996, G. Tiepolo & A.C. Svolenski 716 (EFC, MBM). Rio de Janeiro: Itatiaia, Serra do Itatiaia, Maromba, fl., 23 Oct 1931, C. Porto 2101 (RB). Santa Catarina: Rio do Sul, estrada Rio do Sul-Lontras, fl., 3 Dec 2013, A.L. Gasper et al. 3270 (FURB). Rodeio, borda da floresta, fl., fr., 10 Oct 2015, L.A. Funez 4549 (FURB). Urubici, Salto do rio Avencal, fl., fr., 16 Oct 2004, G. Hatschbach et al. 78097 (MBM). São Miguel D’Oeste, forest above rio Reperi-guaçu, Peperi, fl., fr., 21 Oct 1964, L.B. Smith & R. Reitz 12775 (FLOR, HBR, NY, US). São Paulo: Jundiaí, mata de planalto na Serra do Japi, fl., 11 Aug 1976, H.F. Leitão-Filho & G.J. Shepherd 2536 (MBM, NY, UEC); loc. cit., ca. 10 km SW de Jundiaí, fl., fr., 8 Oct 1976, H.F. Leitão-Filho et al. 3175 (E, MBM, NY, UEC, UFG, US). Salesópolis, Estação Biológica de Boracéia, estrada para a barragem da SABESP no Rio Guaratuba, fl., 5 Sep 1994, R. Simão-Bianchini et al. 505 (RB, SP, UEC).

Etymology.

The epithet " chrysophylla " means golden leaves and is given after the golden hairs that cover the whole plant, but especially the leaves.

Distribution and habitat.

Tradescantia chrysophylla is endemic to Brazil, more precisely to the states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina (Fig. 8 ). It can be found growing as a terrestrial, rupicolous or as an epiphyte, understory in shaded and moist forests.

Phenology.

It was found in bloom and fruit from August to December, but peaking during October.

Conservation status.

Tradescantia chrysophylla possesses a wide EOO (ca. 173,649.709 km22), but a considerably narrow AOO (ca. 36.000 km2). Since it is known from very few and fragmented collections, following the IUCN (2001) recommendations, T. chrysophylla should be considered Endangered [EN, A2cde+ B2ab(ii, iii, iv)+D2].

Discussion.

Tradescantia chrysophylla is morphologically similar to T. cymbispatha C.B.Clarke, T. fluminensis Vell. and T. mundula Kunth due to their indefinite base, creeping stems with ascending apex, saccate cincinni bracts, petals always white, pistil as long as the stamens, seeds with uncleft testa towards the embryotega, and hilum ½ the length of the seed. However, it can be easily differentiated from T. fluminensis and T. mundula by its sessile succulent leaves, blades homogeneously covered by indumentum, and inconspicuous secondary veins (vs. leaves membranous, blades glabrous or unevenly covered by indumentum, and impressed secondary veins), floral buds broadly ovoid (vs. ovoid to narrowly ovoid), and sepals without keels (vs. keeled sepals). Tradescantia chrysophylla is considerably more similar to T. cymbispatha due to their sessile, succulent leaves homogeneously covered by indumenta, inconspicuous secondary veins, and sepals without keels. Nonetheless, in T. chrysophylla the indumentum is velutine to hispid and golden to light brown (vs. strigose and hyaline in T. cymbispatha ), the cincinni bracts are strongly unequal (vs. equal), and the pedicels and sepals are glandular-pubescent with golden to light brown hairs or covered by with a mixture of glandular and eglandular hairs (vs. velutine, covered by eglandular hyaline hairs). Furthermore, T. chrysophylla can be differentiated from almost all the species of T. sect. Austrotradescantia by its golden to light brown indumentum covering almost the entire plant. The only other species known to possess a similarly colored indumentum is T. cerinthoides ( Pellegrini 2015, 2016). Tradescantia chrysophylla can be easily differentiated by its indefinite habit base (vs. definite in T. cerinthoides ), prostrate stems (vs. ascending to erect), saccate cincinni bracts (vs. non-saccate), pistil the same length as the stamens (vs. longer than the stamens), petals always white (vs. ranging from white to pink to lilac), seed not cleft towards the embryotega (vs. cleft), and hilum ½ the length of the seed (vs. longer than ½ the length).

Figures

Figure 2. Tradescantia chrysophylla M. Pell. A habit B detail of the stem and leaf-sheath, showing the hispid indumentum, and detail of the sessile leaf-blade C detail of the hispid hairs of the leaf-blade and of the ciliolate margin D detail of the inflorescence, showing the unequal cincinni bracts E detail of the bracteole F detail of the pedicel and sepals, showing the glandular hairs G frontal view of the flower H stamen, showing the filament with basal, dense and long moniliform hairs, the rhomboid connective, and the ellipsoid anther sacs I detail of the gynoecium, showing the punctate stigma J mature, partially open capsule, still covered by the persistent sepals. K-L seed: K dorsal view of a seed, showing the costate testa and dorsal embryotega L ventral view of the seed, showing the linear hilum. Line drawing by M. A. Rezende.

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.