Cryptanthus micrus Louzada, Wand. & Versieux, 2010

Versieux, Leonardo M., Louzada, Rafael B., Viana, Pedro Lage, Mota, Nara & Wanderley, Maria Das Graças Lapa, 2010, An illustrated checklist of Bromeliaceae from Parque Estadual do Rio Preto, Minas Gerais, Brazil, with notes on phytogeography and one new species of Cryptanthus, Phytotaxa 10, pp. 1-16 : 13-14

Cryptanthus micrus Louzada, Wand. & Versieux , sp. nov. ( Figs. 2L , 5 )

Species nova ad Cryptanthus leopoldohorstii et C. warasii similis sed habito minoribus et foliis brevioribus et angustioribus.

Type: BRAZIL. Minas Gerais: São Gonçalo do Rio Preto, Parque Estadual do Rio Preto , 1200 m elev., 19 July 2009, N. F. O . Mota et al. 1474. (holotype BHCB, isotype SP) .

Plant short caulescent, forming an open rosette, 3–8 cm in diameter, ca. 5 cm high when flowering; leaves 1.5–5 cm long, ca. 30. Sheaths 0.45–0.95 × 0.5–1 cm, chartaceous, deltoid, whitish, margin entire, glabrous on both surfaces. Blades 1.1–4.1 × 0.15–0.3 cm, linear, homomorphic, arching, nearly flat or channeled, coriaceous when dry, somewhat succulent when fresh, green, densely lepidote, on both sides, scales whitish, margin laxly dentate, apex mucronate, prickles 0.5–1 mm long, whitish, antrorse and/or retrorse. Inflorescence sessile, simple or with few two-flowered fascicles. Primary bracts erect, abaxial surface densely lepidote, margins serrulate, apex acute or attenuately acute. Floral bracts ca. 9.5 × 4.5 mm, triangular, erect, ecarinate, membranaceous, white, densely lepidote, margins entire, apex pungent. Flowers ca. 9 mm long excluding the petals, sessile. Sepals ca. 6.5 mm long, 5.5 mm wide, narrowly-ovate, asymmetric, chartaceous, whitish, the adaxial ones distinct from the abaxial ones, ecarinate, free, woolly lepidote, less lepidote inside, margins entire, apex apiculate. Petals ca. 1.1 cm long, lobe ca. 0.3 cm wide, linear spatulate, not fleshy, white, free, margins ciliate or glabrous, apex of the lobes spreading to recurving, obtuse. Petals calli ca. 6 mm long. Stamens exceeding the pistil; filaments free, ca. 4 mm long, white; anthers basifixed, elliptic, ca. 2.5 mm long. Stigma simple-erect, stigmatic area only along the apical margins of the lobes. Epigynous tube absent. Ovary ca. 2.3 mm long, ovoid to near globose. Ovule obtuse, caudate. Fruit globose. Seed trigonous.

Additional specimen examined: BRAZIL. Minas Gerais: São Gonçalo do Rio Preto, Parque Estadual do Rio Preto , 863 m elev., 25 January 2010, N. F. O. Mota & T. B. Jorge 1505 ( BHCB, SP) .

Distribution and Habitat: —This tiny bromeliad was observed growing on quartzite rocks, vertically attached on small cavities, and in rocky fields at 860–1400 m, so far this area is restricted to the PERP.

Etymology: —The epithet refers to the small size of the plant, derived from the Greek µƖκρoς, ‘micros’ meaning small.

Cryptanthus micrus is distinct due to its smaller size and tiny habit when compared to all other species in the genus. It is morphologically similar to xerophytic species belonging to subgenus Hoplocryptanthus Mez (1891: 202) , which is characterized by the presence of leaves that are not constricted above the leaf sheath and by the presence of well developed prickles ( Mez 1891). According to Ramírez-Morillo (1996), additional characters of this subgenus would include the leaf blades covered in trichomes, fragrant bisexual flowers and broad petals. Species belonging to this subgenus occur more commonly in rocky field vegetation at higher elevations (above 800 m) in exposed places on well-drained substrates ( Ramírez-Morillo 1996). Two endemic species of the Diamantina Plateau , that belong to subgenus Hoplocryptanthus , namely C. leopoldohorstii Rauh (1988: 68) and C. warasii Pereira (1978: 252) seem to be the morphological closest relatives of C. micrus . While reviewing the genus, Ramírez-Morillo (1996) noticed the proximity of these two species together with C. caracensis Leme & Gross (1992: 12) and proposed to create a new section to include these, based on the presence of stiff succulent leaves with serrate or dentate margins that are densely covered with white or argent trichomes. However the new taxon can be distinguished from C. caracensis , C. leopoldohorstii , C. warasii , and from C. schwackeanus Mez (1891: 203) that occurs further south, by its shorter and narrower leaf blades and free sepals (vs. connate in different degrees). The indumentum that covers the leaves of C. micrus is sparser when compared to the dense layer of trichomes that covers both surfaces of C. warasii . Cryptanthus micrus has prickles that are laterally compressed and covered by white trichomes and its leaf margins are dentate. Cryptanthus caracensis , C. leopoldohorstii and C. schwackeanus all have serrate margins with shorter prickles. The leaves of C. micrus are somewhat succulent, the prickles are well separated and in cross section the blade is almost planar, while in C. caracensis and C. schwackeanus the prickles are more densely arranged and the blades are clearly canaliculated.

Conservation: —In Minas Gerais the genus Cryptanthus is threatened due to its species’ narrow ranges and endemism ( Versieux & Wendt 2007). Cryptanthus micrus is a rare species that has only two known populations in the PERP, all with small numbers of individuals. Based on the IUCN criteria ( IUCN 2001) C. micrus has the conservation status of Critically Endangered CR B1ab(ii,iii) due its restricted occurrence, the small population sizes and decline in the quality of the habitat, taking into consideration that one population is located right along the border of the park. We suggest that studies in the biology of this species should be carried out in order to understand its reproductive strategies to assure its conservation. The lithophytic life form enables the species to escape from fires, which are quite frequent in these grassland habitats. To avoid other risks, particularly those of with commercial collectors and bromeliad hunters, we suggest that these populations should be well monitored by the PERP authorities.

Figures

FIGURE 2. A. Aechmea nudicaulis var. aureorosea. B. Aechmea phanerophlebia. C.-D. Alcantarea duarteana. C. Individual in the habitat. D. Blooming under cultivation. E. Billbergia amoena var. amoena. F. Billbergia iridifolia var. iridifolia. G.-H. Billbergia zebrina. G. Inflorescence. H. View of the inflorescence from below. I.–J. Billbergia vittata. I. Habit. J. Detail of the flowers. K. Canistrum flavipetalum. L.–M. Cryptanthus micrus. L. Blooming individual. M. Habit. N.–P. Encholirium magalhaesii. N. Habit. O. Inflorescence visited by hummingbirds. P. Detail of the inflorescence at the postanthesis. (Photos: A., B., G., H., I., J., L., N., O., P. by Pedro L. Viana; E., F., M. by Nara F. O. Mota; C. by Rubens Mota, D. Leonardo Versieux).

FIGURE 5. Cryptanthus micrus Louzada, Wand. & Versieux. A. Habit. B. Primary bract. C. Abaxial view of the sepal. D. Lateral view of the sepal. E. Petal showing the opposite stamen and two lateral calli. F. Stigma detail. G. Anther detail. H. Baccate fruit. I. Ventral view of the seed. J. Dorsal view of the seed.