Siderasis fuscata (Lodd.) H.E.Moore, Baileya 4: 28. 1956.

Pellegrini, Marco O. O. & Faden, Robert B., 2017, Recircumscription and taxonomic revision of Siderasis, with comments on the systematics of subtribe Dichorisandrinae (Commelinaceae), PhytoKeys 83, pp. 1-41 : 18-21

3. Siderasis fuscata (Lodd.) H.E.Moore, Baileya 4: 28. 1956. Figs 1A , 2 , 8

Pyrrheima fuscatum (Lodd.) Backer, Handb. Fl. Java 3: 37. 1924.

Pyrrheima loddigesii var. minus (Hassk.) C.B.Clarke in Candolle & Candolle, Monogr. Phan. 3: 272. 1881.

Pyrrheima loddigesii Hassk., Flora 52: 367. 1869, nom. illeg.

Pyrrheima minus Hassk., Flora 52: 368. 1869. Holotype. BRAZIL. Rio de Janeiro. Rio de Janeiro, Corcovado, fl., s.dat., C. Gaudichaud 137 (P barcode P01799823!).

Tradescantia hirsutissima Pohl ex Seub., in Martius, Fl. bras. 3(1): 254. 1855, pro. syn.

Siderasis acaulis Raf., Fl. Tellur. 3: 67. 1837, nom. illeg.

Tradescantia fuscata Lodd., Bot. Cab. 4: t. 374. 1820. Lectotype (designated by Pellegrini 2017). [illustration] Original parchment plate of "The Botanical Cabinet" at the British Museum Library and later published in Loddiges, Bot. Cab. 4: t. 374. 1820. Epitype (designated by Pellegrini 2017). BRAZIL. Rio de Janeiro. Rio de Janeiro, Floresta da Tijuca, FEEMA, Parque Nacional da Tijuca, fl., fr., 7 Nov 2012, M.O.O. Pellegrini 217 (RB barcode RB01093071!).

Description.

Herbs ca. 20-30 cm tall, terrestrial. Roots thin, fibrous, terminal tubers present. Rhizomes buried deep in the ground. Subterraneous stems with internodes elongate, brownish vinaceous to vinaceous with white spots, hirsute, hairs reddish brown. Aerial stems short to inconspicuous, unbranched; internodes weakly to moderately elongate, vinaceous with white spots, hirsute, hairs reddish brown; flagelliform-shoots (ramets) absent. Leaves spirally-alternate, forming a rosette at the apex of the aerial stems, petiolate; sheaths 1-1.5 cm long, hirsute, hairs dark red; petiole 2.7-9.6(-11.4) cm long, terete, canaliculate, C-shaped in cross section, succulent, green to dark green with dense vinaceous spots, spots sometimes covering almost all the petiole, hirsute, hairs red to dark red; blade (4.8-5.6-)7.8-21.1(-23.6) × (2-)3-9.6 cm, succulent, elliptic to obovate to broadly obovate, rarely lanceolate, base cuneate, margins green, flat, densely hirsute, apex acute to obtuse or rounded, slightly curved downwards, adaxially dark green, with a silver to light green, blotched silver to metallic light green along the midvein or not, abaxially light green, with dense vinaceous spots or not; midvein conspicuous, adaxially impressed, abaxially prominent, obtuse, secondary veins 3-6 pairs, adaxially conspicuous, impressed, abaxially inconspicuous, becoming more evident on both sides when dry. Synflorescence composed of a solitary main florescence, or with (1-)2-6(-7) coflorescences. Main florescence (inflorescence) reduced to a solitary pedunculate cincinnus; basal bract 1.5-2.2 × 0.3-1 cm, triangular, cymbiform, dorsally keeled, light pink, hirsute, hairs rusty to dark red, hyaline at the base and margins, apex acuminate; inflorescence main axis inconspicuous; cincinni bract 0.8-2 × 0.2-0.9 cm, triangular, slightly cymbiform, amplexicaulous, pink to vinaceous, hirsute along the midvein, hairs red, base hyaline, margins light brown to golden, glabrous, hyaline, apex acuminate; cincinni 1-3(-4)-flowered, peduncle 1.3-7.4 cm long, light brown, hirsute, hairs red, reflexed in fruit, more rarely also spirally-coiled in fruit; bracteoles absent. Flowers bisexual, actinomorphic, 2-2.8 cm diameter, pedicellate; pedicel 1-5.6 mm long, light brown, hirsute, hairs red, reflexed and elongate in fruit; floral buds 0.8-1.2 × 0.4-0.6 cm, ovoid, light brown to light pink, apex acuminate; sepals 0.8-1.4 × 0.3-0.8 cm, ovate to triangular, membranous, externally light brown, hirsute, hairs red, internally pink to vinaceous, glabrous, margin hyaline, apex acuminate; petals 1.2-1.6 × 1.2-1.5 cm, rhomboid to broadly obtrullate, rarely orbicular, pale lilac to lilac, proximal third gradually white, base cuneate, margin en tire, sometimes irregularly lacerated, glabrous, apex obtuse to rounded, sometimes irregularly lacerated; stamens equal, filaments 3.5-6.3 mm long, straight, white, anthers 1.5-2.1 × 3-4.2 mm, anther sacs white, connectives quadrangular, white; ovary glo bose, 2.9-3.7 × 2.3-3.2 mm, white, densely hirsute, hairs white at base, gradually becoming rusty, then dark red terminally, style 3.1-4.4 mm long, straight, white; stigma annular-truncate, white, papillate. Capsules ellipsoid to fusiform in outline, 1.1-1.6 × 0.5-0.8 cm, smooth, light greenish brown with minute purple spots near the base and 3 longitudinal atro-vinaceous stripes along the septa, when mature light brown with 3 longitudinal black stripes along the septa, hirsute, hairs red. Seeds obconic to ellipsoid, dorsoventrally compressed, ventrally slightly ridged, 2.9-4.4 × 2.9-3.6 mm, grey to light grey, testa foveolate, ventral face slightly cleft on the side towards the embryotega; hilum longer than ½ the length of the seed; embryotega semilateral; aril hyaline, inconspicuous.

Specimens examined.

BRAZIL. Rio de Janeiro: Niterói, Itaipu, P.E. Serra da Tiririca, Alto Mourao , fl., 15 Jan 1982, V.F. Ferreira et al. 2104 (RB); divisa entre os municípios de Niterói e Maricá, entre Itacoatiara e Itaipuaçu, Alto Mourão, fl., 11 Sep 2007, A.A.M. Barros & M. Pontes 3127 (RFFP). Rio de Janeiro, s.loc., fl., s.dat., Mr. Boag s.n. (K barcode K001190685); s.loc., fl., s.dat., Mrs. Graham s.n. (K barcode K001190684); s.loc., fl., 1816-1821, A. Saint-Hilaire A/683 (P); s.loc., fl., fr., 1832, Riedel s.n. (P barcodes P01730357, P01730358); Corcovado, fl., fr., 1831-1833, C. Gaudichaud 337 (P 3 ex); fl., Jul 1837, G. Gardner 847 (K barcode K001190683); Cova da Onca , fl., 15 Aug 1861, A.M. Glaziou 527 (NY, P); fl., 17 Aug 1869, A.M. Glaziou 4285 (P 2 ex); fl., Jul 1878, J. Miers 3534 (K, P); fl., fr., 5 Dec 1889, P. Schwacke 6699 (RB); fl., 5 May 1892, A. Ducke s.n. (RB 64); Tijuca, rio Trapicheiros ( Fabrica da Cheetos ), fl., Nov 1925, J.S. Kuhlmann s.n. (RB 19282, U barcode U1210766); fl., fr., 4 Mar 1943, A.P. Duarte & C.T. Rizzini 8 (RB); fl., 6 Nov 1944, P. Occhioni 50 (RB); Parque Natural da Tijuca , Matas do Pai Ricardo , fl., 29 Oct 1975, D.S. Araújo et al. 883 (GUA); fl., 30 Oct 2013, M.O.O. Pellegrini 404 (RB); fl., 15 Nov 2013, L.S.B. Calazans & R.T. Valadares 234 (RB); road to Vista Chinesa, next to the Biological Station , fl., 18 Aug 1960, C. Angeli 230 (GUA); Setor das Paineiras , next to Pedra do Beijo , fl., 15 Nov 1965, J.P.P. Carauta 286 (GUA); road to Vista Chinesa, fl., fr., 31 Oct 1969, J.P.P. Carauta 923 (GUA); Santa Cruz, fl., 6 Jul 1972, E. Lagasa s.n. (HB 71875); Pedra da Gavea , fl., 13 Jul 1966, D. Sucre 1304c (HB, RB); Alto da Boa Vista , Morro Queimado, next to the FEEMA building, fl., 26 Oct 2000, F. Pinheiro et al. 557 (HB); Estrada da Guanabara , Parque Lage, 25 Jan 1968, fl., D. Sucre 2161 (RB); Reserva Florestal do Jardim Botanico , fl., 19 Jan 1969, D. Sucre & P.J.J. Braga 4472 (RB); fl., 22 Dec 1971, D. Sucre 8152 (RB); Matas da Lagoinha , fl., 18 September 1946, P. Occhioni 692 (RB); fl., 6 Mar 1978, V.F. Ferreira et al. 256 (RB); fl., 11 Nov 1946, P. Occhioni 781 (RFA); brook trail between Paineiras and Jardim Botânico, fl., 4 Dec 1928, L.B. Smith s.n. (US barcode US1540545) .

Specimens examined (cultivated).

ENGLAND. Greater London: London, Royal Botanic Gardens, Kew , cultivated at the Nepenthes House , Kew , fl., 1908, s. leg. s.n. (K); fl., fr., Jun 1879, N.L. Brown s.n. (K); fl., 1967, Mason 458/61 (K); fl., 9 Jul 1974, Jodrell Laboratory s.n. (K 458-61-45801) .

Etymology.

The epithet " fuscata " means dark-colored, in allusion to the red to bright red hairs that cover almost the entire plant, in opposition to the normally hyaline hairs in most Commelinaceae .

Distribution and habitat.

Siderasis fuscata is endemic to the municipalities of Rio de Janeiro (with several localities inside Floresta da Tijuca) and Niterói (with just one locality, Alto Mourão), in the Rio de Janeiro state (Fig. 2 ). It occurs in the vegetation on hillsides (mata de encosta) near the littoral, in shady areas with shallow and rocky soil.

Phenology.

It blooms from August to May and fruits from January to May, although fructification seems to be an uncommon event since few fruiting specimens were seen or collected.

Common name.

" violeta-silvestre ", " orelha-de-urso ", " pelo-de-urso ", " trapoeraba-peluda ", "brown spiderwort", "bear ears".

Conservation status.

Siderasis fuscata is one of the few Commelinaceae included in the Lista da Flora Brasileira Ameaçada de Extinção (List of the Threatened Brazilian Flora; Fundação Biodiversitas 2009) and in the Lista Oficial das Espécies da Flora Brasileira Ameaçadas de Extinção (Official List of the Threatened Species of the Brazilian Flora; MMA 2008), at both lists classified as Data Deficient (DD). In the recently published Commelinaceae chapter of the Livro Vermelho da Flora do Brasil (Red Book of the Brazilian Flora; Aona-Pinheiro et al. 2013), S. fuscata is classified as Endangered (EN) by the authors, based on existing published data.

The subpopulation from Niterói is disjunct from the others in Rio de Janeiro, due to the urban area of both cities. It possesses a considerably small EOO (ca. 7000 km²), with the population being severely fragmented. Despite all the extant subpopulations being inside conservation units (i.e. Parque Nacional da Tijuca and Parque Estadual Serra da Tiririca), they are considerably small, composed mainly of clonal individuals, with no more than 30 mature individuals. Only a small number of fertile individuals can be found during the flowering season in each population, and very few fruits are produced. All these areas are extremely susceptible to real-estate development, deforestation, and have many invasive species, with areas like Parque Estadual Serra da Tiririca being especially affected by human-related forest fires. The subpopulations from Pedra da Gávea and Corcovado are probably extinct, or nearly so, since no recent collection in either areas is known by the authors. A total of 250 mature individuals is estimated for the overall population, based on our field observations. Added to the above factors, S. fuscata is appreciated as an ornamental plant all over the world due to its exotic foliage and beautiful flowers, so the few known extant subpopulations are also a target of illegal collection for exotic plant growers from all over the world. Thus, following the IUCN criteria ( 2001), we suggest S. fuscata be considered Critically Endangered [CR, A2abcde+B1ab(i,ii,iii,iv,v)+B2a(i, ii)+ C2a(i)+D2].

Affinities.

Siderasis fuscata is similar to S. albofasciata in their variegated leaf blades, and similar to S. almeidae and S. medusoides in their white anthers. Nevertheless, it can be readily distinguished from all species of Siderasis by its petiolate leaves, red to bright red indumentum covering almost the entire plant (vs. sessile to subsessile leaves, light brown to hyaline indumentum), cincinni without bracteoles (vs. bracteoles present), acuminate flower buds and sepals (vs. obtuse to rounded), androecium and gynoecium completely white (vs. androecium and gynoecium partially bluish, lilac or purple), ovary and capsules hirsute (vs. velutine, hispid or lanate), seeds with light grey to grey and foveolate testa (vs. medium to dark brown and rugose or scrobiculate testa), and hyaline and inconspicuous aril (vs. aril cream-colored, slightly translucent and thick).

Figures

Figure 1. Floral morphology of subtribe Dichorisandrinae s. l. A-C Siderasis Raf. emend M. Pell. & Faden: A S. fuscata (Lodd.) H. E. Moore B S. albofasciata M. Pell. C S. zorzanellii M. Pell. & Faden. D-L Dichorisandra J. C. Mikan: D D. acaulis Cogn. E D. hexandra (Aubl.) C. B. Clarke F D. thyrsiflora J. C. Mikan G D. paranaensis D. Maia et al. H D. nana Aona & M. C. E. Amaral I D. incurva Mart. J D. penduliflora Kunth K D. sagittata Aona & M. C. E. Amaral L D. radicalis Nees & Mart. M Cochliostema odoratissimum Lem. N Geogenanthus rhizanthus (Ule) G. Brueckn. O Plowmanianthus panamensis Faden & C. R. Hardy. Photographs A-B, D-G, J by M. O. O. Pellegrini, C by J. P. F. Zorzanelli, H by V. Bittrich, I by G. H. Shimizu, K by J. L. Costa-Lima, L by M. A. N. Coelho, M by R. Moran, N by D. Scherberich, and O by C. R. Hardy.

Figure 2. Distribution map of Siderasis Raf. emend. M. Pell. & Faden. Blue circles - S. albofasciata; Blue triangles - S. almeidae; Red circles - S. fuscata; Red triangles - S. medusoides; Blue square - S. spectabilis; Red Square - S. zorzanellii; BA - state of Bahia; ES - estate of Espirito Santo; RJ - estate of Rio de Janeiro.

Figure 8. Siderasis fuscata (Lodd.) H. E. Moore. A habit, showing a mature rosette and green leaves B detail of leaf with a silvery blotch along the midvein C detail of the canaliculate petiole, showing the rusty hairs D detail of the bright-red hirsute indumentum E upper view of a fertile rosette, showing many lilac flowers open at the same time F front view of a pale-lilac flower, showing the lacerated petals and completely white androecium and gynoecium G detail of the androecium and the gynoecium H detail of a mature capsule, showing the atro-vinaceous longitudinal stripes I detail of an open capsule, showing the biseriate to partially uniseriate, inconspicuously arillate seeds, with grey foveolate testa. Photographs by M. O. O. Pellegrini.