DOI: 10.5061/dryad.7j5h2
title: Data from: Siderasis albofasciata sp. nov. (Commelinaceae), endemic to the state of Espírito Santo, Brazil, and the typification of S. fuscata

description: A new species of Siderasis from the state of Espírito Santo is here
 described. This new species is readily differentiated from S. fuscata by
 its sessile to subpetiolate leaves covered by hyaline to light-brown
 indumenta, blades with a well-defined white stripe along the midvein on
 the adaxial side of the blade, main axis of the main florescence elongate,
 thyrsi reduced to one elongate cincinnus, bracteoles present, anthers
 purple to bluish–purple, filaments and style apically purple to
 bluish–purple, aril cream-colored and slightly hyaline, and by the
 production of unique axillary flagelliform-shoots after the flowering
 period. I present a description of this new species, along with
 illustrations, a distribution map, comments on conservation assessment,
 ecology and taxonomy, and a table comparing the new species with the only
 other accepted species in Siderasis. Furthermore, I designate a lectotype
 and an epitype for S. fuscata.
description: Fig. 1- Siderasis
 albofaciataFig. 1. Siderasis
 albofaciata M.Pell. A, habit, showing the well-defined white stripe along
 the midvein of the leaves and the flagelliform-shoots with terminal
 rosettes. B, detail of the abaxial side of the leaf, showing the
 light-brown lanate indumenta. C, detail of the adaxial side of the leaf,
 showing the light-brown hispid indumenta. D, detail of the inflorescence,
 showing the solitary cincinnus. E, flower F, detail of the androecium and
 the gynoecium. G, detail of the capsules, the left one immature with
 evident accrescent sepals and the right one mature. H, detail of an open
 capsule, showing the uniseriate to partly biseriate arillate seeds. I,
 Dorsal view of a seed, showing the semi-lateral embryotega and the
 cream-colored, slightly translucent and thick aril. F by L. Kollmann (L.
 Kollmann et al. 11839, MBML), remaining photos by M.O.O. Pellegrini
 (M.O.O. Pellegrini et al. 337, RB, US).Fig. 2- Siderasis
 inflorescenceFig. 2. The
 inflorescence of Siderasis Raf. A, inflorescence diagram. B, rosette apex
 of S. albofaciata, showing: the main florescence (primary thyrse) with a
 flower at post-anthesis and a flower bud; the developed secondary thyrse
 with a flower at anthesis (arrow); and a young tertiary thyrse (arrow). C,
 synflorescence of S. fuscata, showing: the condensed synflorescence main
 axis and the long-pedunculate cincinni. P= prophyll; pB= peduncle bract on
 main synflorescence axis; *= aborted or dormant apex of main inflorescence
 axis (usually not observed); B= cincinnus bract; b= bracteole; f= flower;
 1º bud= bud terminating cincinnus; 2º bud= bud in axil of peduncle bract
 with potential to develop into a secondary thyrse (coflorescence); 2º
 cincinnus= cincinnus of the secondary thyrse (coflorescence). Modified
 from Hardy and Faden (2004).Fig. 3- Lectotype of
 Tradescantia fuscataFig. 3. Lectotype of
 Tradescantia fuscata Lodd. Photo courtesy of The Natural History Museum,
 London. This image is in the public domain and can be accessed through the
 Biodiversity Heritage Library.Fig. 4- Siderasis
 fuscataFig. 4. Siderasis
 fuscata (Lodd.) H.E.Moore. A, habit, showing the petiolate leaves with
 silvery blotch along the midvein. B, detail of the bright-red hirsute
 indumenta. C, detail of the synflorescence detached from the rosette,
 showing the inconspicuous main axis and ebracteolate cincinni. D, upper
 view of a fertile rosette, showing many lilac flowers open at the same
 time. E, front view of a pale-lilac flower, showing the lacerated petals
 and completely white androecium and gynoecium F, detail of a mature
 capsule, showing the atro-vinaceous longitudinal stripes. Photos by M.O.O.
 Pellegrini (M.O.O. Pellegrini 217, RB).Fig. 5-Siderasis
 mapFig. 5. Distribution map
 of Siderasis Raf. Squares– Siderasis albofaciata M.Pell.; Circles– S.
 fuscata (Lodd.) H.E.Moore.