Distribution - The species is only known from the Municipio of Santo Antonio do ltambe, where it occurs inside of Parque Estadual do Pico do ltambe in humid quartizitic rock outcrops near to waterfalls and gallery forest, between 700--900 m.
Etymology - Refers to the type locality: the Municipio of Santo Antonio do Itambe, and the Parque Estadual do Pico do Itambe, at Minas Gerais State.
Additional Specimens Examined - BRAZIL Minas Gerais: Municipio de Santo Antonio do Itambe, Parque Estadual do Pico do Itambe, 15 Dec 2005 (fr) Louzada et al. 6 (SP); 10 Oct 2006 (fr), Louzada et al. 30 (SP); 10 Oct 2006 (fr). Versieux et al. 302 MO, SEL, SPF).
TYPE: Brazil. Minas Gerais: Santo Antonio do Itambe, Parque Est. do Pico do Itambe, margem esquerda do Rio Preto, proximo a cachoeira da Fumaca, ca. 850 m, 29 Ago. 2003. L M Versieux 149 & A. P. G.. Faria (fl. in cultivation, Botany Res. Greenhouse, Univ. Fed. do Rio de Janeiro, 21 Ago. 2004) (holotype, HB; isotype,, BHCB, RFA, SEL, SP). Figures 1, 2C-F, 3.
Species nova Orthophytum supthutii E. Gross & Barthlott. affinis sed laminis foliorum supra albo-zonatis sepalis sublineris et etiam petalis albis base appendicibus brevioribus differt.
Plant lithophytic, forming mats, 9 cm high when flowering, short-caulescent, propagating by elongated basal stolons;
stolons ca. 10 cm x 3 mm, covered by reduced light brown, narrowly triangular cataphylls, ca, 1.5 cm,
Leaves ca. 30, suberect to spreading, arcuate-recurved toward apex at anthesis;
leaf sheath, widely ovate-elliptic, 1-1.5 X 2-2.5 cm, glabrous, lustrous, pale yellow becoming greenish yellow and spinulose toward apex;
leaf blade narrowly triangular, apex soft, filiform-caudate, (8.5-)12-21 X (0,6)1-1.7 cm, green, slightly canaliculate toward base, thinner in texture and nearly flat toward apex, abaxially distinctly nerved, subdensely to densely white-lepidote, trichomes asymmetrical, arranged along the midnerves, not obscuring leaf color, adaxially trichomes forming white cross-bands, margins spinulose, spines triangular-uncinate, distinctly antrorse, yellowish green toward apex, 0.5-1 mm long, 2-4 mm apart.
Inflorescence sessile, pseudosimple to inconspicuously bipinnate, inconspicuously subcorymbose, sunk in the center of the rosette, ca. 4 X 3 cm, ca. 20-flowered;
primary bract foliaceous, gradually reduced in size inward, 7-13 X 1.5-2 cm, becoming yellowish green or reddish green et anthesis;
fascicles ca. 13, inconspicuous, 1- to 2-flowered, ca. 4.3 X 1 cm, compressed, nearly sessile, peduncle complanate, ca. 1 X 5 mm;
floral bract narrowly triangular, apex acuminate with a recurved apiculus, 11 X 5-6 mm, membranaceous, glabrous, finely nerved, entire, sharply carinate.
Flowers 38-40 mm, sessile or nearly so, odorless or with soft sweet smell, diurnal;
sepals narrowly triangular-lanceolate, apex acuminate-attenuate, 14-15 X 3-4 mm, connate at base for ca. 1 mm, symmetric or nearly so, glabrescent, finely nerved, erect, white, membranaceous, entire, sharply carinate;
corolla erect and tubular at anthesis,
petals subspatulate, apex subobtuse and inconspicuously emarginate, 30-32 X 10 mm, free, glabrous, white, bearing at base 2 sublinear-lanceolate, acuminate to irregularly bidentate appendages, 3-4 X 1 mm;
stamens included, Filaments 16-20 mm, terete, white, free or nearly so, anthers oblong, ca. 2 mm, base slightly sagittate, apex minutely apiculate, dorsifixed near the base;
pollen grains single, ellipsoid, monocolpate, exine reticulate, ca. 60 X 22 micron;
ovary obovate, trigonous, 6 X 4-5 mm, white, glabrous, epigynous tube ca .1mm, placentation axile;
style included, white, distinctly surpassing the anthers, 28-30 mm;
stigma conduplicate, weakly spiral, 2-3 mm, white, inconspicuously papillose;
ovules numerous, obtuse, restricted to upper 1/3 of the ovary locule.
Fruits white becoming green toward apex, fleshy, trigonous, ca. 8 X 4 mm;
seeds ca. 10, elliptic to ovoid, ca. 2 X 0.8 mm, yellowish white.
Orthophytum itambense can be distinguished from the most similar taxon, 0. supthutii in several characteristics as pointed out in the following key:
la. Leaf blade glabrous and lustrous on the adaxial surface; sepals unequally connate at base for 2-5 mm; petals orange-yellow, petal appendages 5 -7 mm long => O. supthutii
lb. Leaf blade with trichomes forming white cross-bands on the adaxial surface: sepals nearly free, connate at base for ca. 1 mm only; petals white, petal appendages 3-4 mm long. => O. itambense
Orthophytum supthutii may he misidentified with Cryptanthus schwackeanus Mez, in herbaria, although the latter can be distinguished from both O. supthutii and O. itambense by its elliptic petals connate by 2-3 mm without appendages.
Leaf anatomy has also indicated several differences that can be used to separate Orthophytum itambense from O. supthutii. First, the adaxial hypodermis of O. itambense has four to five layers, and the first two of these layers have thickened, lignified cell walls. The hypodermis of O. supthutii consists of five to six layers of cells, and only the first one has cells with thickened, lignified walls.
Second, in O. itambense the chlorenchyma is located in the inner half of the mesophyll with seven to eight layers, and in O. supthutii, while it has similar chlorenchyma, there are 10 to 11 cell layers.
Third, peltate trichomes in O. itambense have a stalk composed of three basal cells, while in O. supthutii it is composed of only two basal long cells.
Finally, in the abaxial epidermis, stomata are projected in O. itambense (Fig. 2C), while they are only weakly projected in O. supthutii (Souza, pers. obs.).
Leme (2004a) proposed a provisional division for Orthophytum into two complexes and six subcomplexes of species, in which O. supthutii was segregated alone in subcomplex supthutii by its stemless habit, the similar color of the inner and outer leaves at anthesis, sessile inflorescence, and by the unusual bright orange-yellow petals. In fact, O. supthutii has been an intriguing species mainly because of its orange-yellow petals, with no obvious closely related taxon within the genus, and thus the basis for the Gross and Barthlott (1990) suggestion that a new subgenus be created for this species.
The inclusion of O. itambense as the second species in this subcomplex supthutii provides new impetus for further analyses of these two unique taxa and a better understanding of their position in the genus.
Distribution, habitat, and conservation status.
Orthophytum itambense grows on quartzite outcrop, at ca. 850 m elevation and is usually associated with Eriocaulaceae, Velloziaceae, and Xyridaceae species. It grows inside gallery forest at shaded and moist spots along the margins of Rio Preto, cachoeira da Fumaca, in Pico do Itambe State Park, located at Santo Antonio do Itambe (Figs. 2A, B). Despite being under legal protection, Pico do Itambe State Park still suffers environmental aggressions such as fires from adjacent agricultural areas. These fires can reach gallery Forests, especially during the dry season (winter). Land clearing is also a problem around the protected area, thus compromising the natural populations of O. itambense and its habitat.
Similar conservation problems affect its closest relative, Orthophytum supthutii, which also has a restricyed distribution even within the limits of its area of occurrence at the Cipo range (Leme, 1995) about 100 km south from Santo Antonio do Itambe. According to Gross and Barthlott (1990) and Rauh and Gross (1990), O. supthutii grows as a lithophyte on vertical rocky walls in deciduous forests or under full sun on rocky soil at altitudes above 1000 m.
Based on the IUCN criteria (IUCN, 2001), Orthophytum itambense and O. supthutii can be given the conservation status of Critically Endangered CR B1ab(ii, iii) and Endangered EN B1ab(ii, iii), respectively, due to their restricted occurrence area, habitat loss, and small population size. This situation enforces further distribution analyses and conservation projects with these taxa.
Paratypes. BRAZIL. Minas Gerais: Santo Antonio do Itambe. Parque Est, do Pico do Itambe, cachoeira da Fumaca, ca. 876 m, 16 Dec. 2005, R. B. Louzada 6, L M. Versieux &. A M Calvente (SP), ca. 830 m, 10 Oct. 2006 L M Versieux 302. A M Calvente & R. B. Louzada (MO. SEL. SPF).