Tradescantia chrysophylla M.Pell., PhytoKeys 80: 9. 2017.

Pellegrini, Marco O. O., 2018, Wandering throughout South America: Taxonomic revision of Tradescantia subg. Austrotradescantia (D. R. Hunt) M. Pell. (Commelinaceae), PhytoKeys 104, pp. 1-97 : 15

3. Tradescantia chrysophylla M.Pell., PhytoKeys 80: 9. 2017. Figs 12 , 13

Tradescantia serrana Hassemer & Funez, in Hassemer et al. Phytotaxa 312 (2): 214. 2017. Holotype. BRAZIL. Santa Catarina: Urubici, SC-110, entre Bom Retiro e Urubici, fl., 12 Feb 2016, G. Hassemer & L.A. Funez 888 (FURB no. 54402!; isotypes: B n.v., C n.v., W n.v.). Syn. nov.

Holotype.

BRAZIL. São Paulo: Biritiba Mirim, Estação Biológica de Boracéia, fl., 24 Nov 1983, A. Custódio Filho 1910 (RB barcode RB00972738!; isotype: SP barcode SP195458!).

Description.

Herbs ca. 10-40 cm tall, with an indefinite base, terrestrial or rupicolous, rarely epiphytes. Stems prostrate with ascending apex, delicate to slightly succulent, little to densely branched; internodes 1.5-8.2 cm long at base, distally shorter, medium to dark green or vinaceous, velutine to hispid, hairs golden to light brown. Leaves distichously-alternate, sessile; ptyxis involute; sheaths 0.4-1 cm long, light to medium green to vinaceous, sometimes with green striations, velutine to hirsute, margin densely setose, hairs golden; blades 1.8-7.6 × 0.9-3.4 cm, elliptic to broadly elliptic or lanceolate to ovate to broadly ovate, flat, succulent, velutine to hispid on both sides, hairs golden to light brown, adaxially medium to dark green, abaxially light to medium green or vinaceous, turning black to dark brown or olive-green when dry, base cordate to obtuse, margin ciliolate, slightly revolute, 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, velutine to hispid, hairs golden to light brown; cincinni bracts 0.9-6.6 × 0.3-3.1 cm, unequal to strongly unequal to each other, elliptic to ovate to broadly ovate, leaf-like, velutine to hispid, hairs golden to light brown, medium to dark green, abaxially light to medium green or vinaceous, base cordate to obtuse, saccate, margin ciliolate, slightly revolute, apex acute; double cincinni (4-)6-20-flowered. Flowers 1.1-1.6 cm diam., pedicels 0.6-1.3 cm long, glandular-pubescent; floral buds broadly ovoid; sepals 4.7-6 × 2.2-4 mm, not keeled, light to medium green, glandular-pubescent or with a mixture of glandular and eglandular, golden to light brown hairs; petals 7.2-9 × 4.6-6.2 mm, white; filaments 5.4-6.2 mm long, anthers 0.6-1 × 0.3-0.7 mm; ovary 0.8-1.7 × 0.7-1.4 mm, style 3.8-4.6 cm long; pistil the same length as the stamens. Capsules 2.7-3.2 × 2.2-2.8 mm. Seeds 1.1-1.5 × 1.0-1.4 mm, testa grey to greyish-brown, not cleft towards the embryotega, costate; hilum ½ the length of the seed.

Specimens seen.

BRAZIL. Paraná: Campo Largo, Caverna do Pinheirinho, fl., fr., 13 Oct 1996, G. Tiepolo & A.C. Svolenski 716 (EFC, MBM). Piraquara, Mananciais da Serra, fl., 10 Oct 1967, L.T. Dombrowski & Y.S. Kuniyoshi 2697 (MBM, US). Sapopema, Barra da Balsa Rio Tibagí, Fazenda Guaporé, fl., fr., 22 Jul 1989, A.O.S. Vieira et al. 366 (FUEL). São José dos Pinhais, Guaricana, 28 Sep 1983, P.I. Oliveira 746 (MBM, US). Rio de Janeiro: s.loc., fl., 1816-1821, A. Saint-Hilaire S44 (P barcodes P02174007, P02174010); Itatiaia, Serra do Itatiaia, Maromba, fl., 23 Oct 1931, C. Porto 2101 (RB); Resende, Parque Nacional do Itatiaia, Maromba, fl., fr., 14 Aug 1967, J. Mattos & N. Mattos 14774 (K, SP); Teresópolis, administração do Parque Nacional da Serra dos Órgãos, fl., 11 Jul 1956, A. Castellanos 21648 (RB); fl., 14 Jul 2011, J.A. Lombardi 8616 (HRCB); trilha na descida do abrigo 4, fl., 26 Oct 2012, D. Araújo et al. 116 (HRCB). Rio Grande do Sul: Guaíba, Parque Natural Municipal Morro José Lutzenberger, fl., 10 Dec 2015, M.O.O. Pellegrini & R.F. Almeida 480 (RB). Santa Catarina: Lages, Morro do Espigão, fl., fr., 25 Dec 1956, J. Mattos 3897 (HAS). 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 (CORD, FLOR, HBR, K, NY, P, R, 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); ca. 10 km SW de Jundiaí, fl., fr., 8 Oct 1976, H.F. Leitão-Filho et al. 3175 (E, K, MBM, NY, UEC, UFG, US, VIC); 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). São Paulo, Chácara dos Morrinhos, fl., 11 Oct 1941, B. Pickel 5444 (IPA, US); São Paulo, Serra da Cantareira, fl., Oct 1958, R. Schnell 8523 (P).

Distribution and habitat.

Tradescantia chrysophylla is endemic to Brazil, more precisely to the states of Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul; in the Atlantic Forest domain (Fig. 13 ). It can be found growing as a terrestrial, rupicolous or as an epiphyte understorey in shaded and moist forests.

Phenology.

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

Etymology.

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

Conservation status.

According to Pellegrini et al. (2017), T. chrysophylla possesses a wide EOO (here updated to ca. 234,968.601 km2), but a considerably narrow AOO (ca. 60.000 km2). It is known from very few and fragmented collections and, following the IUCN (2001) recommendations, it should be considered as Endangered [EN, A2cde+B2ab(ii, iii, iv)+D2].

Comments.

Tradescantia chrysophylla is morphologically similar to T. cymbispatha , T. fluminensis and T. mundula due to their indefinite base (Fig. 12 , B), prostrate stems with ascending apex (Fig. 12A, B ), involute ptyxis, saccate cincinni bracts, white petals (Fig. 12H, I ), pistil as long as the stamens, seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 12J ). However, it can be easily differentiated from T. fluminensis and T. mundula by its sessile succulent leaves, blades evenly 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. narrowly ovoid to ovoid) and sepals without keels (vs. keeled sepals). Tradescantia chrysophylla is considerably more similar to T. cymbispatha due to their sessile, succulent leaves evenly covered by indumentum, inconspicuous secondary veins and sepals without keels. Nonetheless, in T. chrysophylla , the indumentum is velutine to hispid and golden to light brown but sometimes becoming light-brown when over-exposed to the sun (vs. strigose and hyaline in T. cymbispatha ), the cincinni bracts are unequal to strongly unequal (vs. equal) and the pedicels and sepals are glandular-pubescent with golden to light brown hairs or covered by a mixture of glandular and eglandular hairs (vs. velutine, covered exclusively by eglandular hyaline hairs). Furthermore, T. chrysophylla can be differentiated from almost all the species of T. subg. Austrotradescantia by its golden to light brown indumentum covering almost the entire plant. The only other species known to possess a similarly coloured indumentum are T. cerinthoides ( T. crassula group; Pellegrini 2015, 2016) and T. tucumanensis ( T. tenella species complex; Pellegrini 2017). 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). Tradescantia chrysophylla and T. tucumanensis can be confused due to their similar habit, light brown to golden indumentum and asymmetrical cincinni bracts. Nonetheless, both species are easily differentiated by their non-overlapping distributions (endemic to Brazil in T. chrysophylla vs. restricted to the Tucumano-Boliviano Forest in T. tucumanensis ), leaf morphology (leaves sessile, succulent, with inconspicuous secondary veins in T. chrysophylla vs. subpetiolate, membranous to chartaceous, with impressed secondary veins in T. tucumanensis ). Finally, T. chrysophylla is easily identified in dried specimens, since it becomes peculiarly dark brown to black, added to the large epidermal domes in the leaf-blades.

Hassemer et al. (2017) describe T. serrana as a new species, known from a sole collection and endemic to the state of Santa Catarina. They compare their new species with T. umbraculifera , with which it bears very little resemblance. They also compare T. serrana with T. chrysophylla , differing both species based on the shape of their leaves, concentration of hairs on both sides of the blades, the presence of dorsal keels in the sepals, the posture of the petals (i.e. flat vs. plicate) and the relative length between the androecium and the pistil. Nonetheless, the sepals’ midvein was misinterpreted by the authors as representing dorsal keels (which, for instance, can be easily observed in T. fluminensis ; Fig. 6B ), the repandous petals as being plicate (which is only known to occur in T. atlantica and T. fluminensis ; Fig. 6D-F ), but they failed to realise that the relative length between the stamens and pistil used by me in my MSc thesis ( Pellegrini 2015), is actually approximate and that in the T. crassula group, the pistil is considerably longer than the stamens, as opposed to the approximately equal length in the T. fluminensis group. Tradescantia chrysophylla and T. serrana share the sessile and succulent leaves with inconspicuous secondary veins, blades velutine to hispid with light brown to golden hairs, unequal to strongly unequal cincinni bracts and pedicels and sepals glandular-pubescent or with a mixture of glandular and eglandular hairs. Tradescantia serrana undoubtedly represents nothing more than a synonym of T. chrysophylla and ishere treated as such.

Figures

Figure 6. Floral morphology in Tradescantia subg. Austrotradescantia. A-C floral buds A floral bud of T. cerinthoides, showing the vinaceous coloration, densely hispid indumentum and absence of dorsal keels in the sepals B floral bud of T. fluminensis, showing the medium green colouration and pilose eglandular hairs restricted to dorsal keels C floral bud of T. tenella, showing the green colouration, glandular-pubescent indumentum and the presence of dorsal keels in the sepals D-H flowers D front view of a flower of T. atlantica, showing the plicate petals E front view of a flower of T. fluminensis, showing the plicate petals F side view of two flowers of T. fluminensis, showing the plicate petals and the deflexed flowers at post-anthesis G front view of a flower of T. tenella, showing the flat petals H front view of a flower of T. umbraculifera, showing the flat and elliptic petals. Photos by M. O. O. Pellegrini.

Figure 12. Tradescantia chrysophylla M. Pell. A habit, showing the prostrate stems (removed) B detail of the ascending apex C-D detail of the stem and leaf-sheath, showing the velutine to hispid indumentum C medium green to reddish-green internodes (removed) D vinaceous internodes E-G leaves E adaxial side F vinaceous abaxial side G light green abaxial side (removed) H-I inflorescence (removed) H upper view of an inflorescence, showing unequal cincinni bracts and a front view of a flower (removed) I front view of a flower (removed) J dorsal and ventral views of the seed, showing the costate testa not cleft towards the embryotega, and the hilum ca. 1 / 2 the length of the seed. Photos by M. O. O. Pellegrini. See the Erratum note.

Figure 13. Distribution of Tradescantia chrysophylla M. Pell. Orange- Cerrado; Red- Caatinga; Olive-green- Pampa; Dark green- Atlantic Forest.