Bromeliaceae and Orchidaceae on rocky outcrops in the Agreste Mesoregion of the Paraíba State , Brazil 1

(Bromeliaceae and Orchidaceae on rocky outcrops in the Agreste Mesoregion of Paraíba State, Brazil). The present study consists of the floristics-taxonomic survey of Bromeliaceae and Orchidaceae on rocky outcrops located at an Atlantic Forest-Caatinga transition area in Paraíba State, northeast of Brazil, in order to provide data for the implementation of the biota conservation’s policies, especially of the flora associated to rocky environments of Paraíba State, given that the taxonomic studies focusing on such families in this state are still incipient. During the study, ten species in six genera of Bromeliaceae and six species in five genera of Orchidaceae were recorded. The treatment includes keys for recognition of the species of families, morphological descriptions, illustrations, geographic distribution data, and comments on the phenology of the species.


Introduction
The Agreste Mesoregion of the Paraíba State, area of semiarid climate is notable for having a meaningful set of granite and gneissic rocky outcrops that abruptly develope above the surrounding landscape (Sarthou et al. 2001, Porembski 2007, Araújo et al. 2008).These rocky outcrops, usually of Pre-Cambrian origin, present distinctive edaphic and microclimatic conditions, such as drought stress, insolation and high temperatures (Barthlott et al. 1993, Porembski 2007, Araújo et al. 2008).They are distributed throughout the world, especially in tropical regions, being particularly common in the Northeast region of Brazil (Porembski et al. 1998, Sarthou et al. 2003, Pitrez 2006).
Bromeliaceae Juss.and Orchidaceae Juss.are common families on rocky outcrops and considered as characteristic groups in the vegetation of these environments (Barthlott et al. 1993, Meirelles et al. 1999, Sarthou et al. 2003, Porembski 2007, Pessoa & Alves 2014).Both have their main diversity centers in tropical areas, being composed, respectively, of ca.3,200 species in 58 genera (Luther 2008) and 24,500 species in 785 genera (Dressler 2005, Pessoa et al. 2011).It is estimated that ca.1,300 species of bromeliads and 2,450 of orchids occur in Brazil; of which 412 and 606 species, respectively, are reported from the northeast region (Barros et al. 2014, Forzza et al. 2014).
Despite the substantial representation, floristic inventories and taxonomic treatments covering Bromeliaceae and Orchidaceae in bedrock settled in the Paraíba State are still missing.Thus, given the need to improve the knowledge of the richness of monocotyledons as well as to protect their representatives and respective areas this work presents the floristics-taxonomic study of Bromeliaceae and Orchidaceae on two rocky outcrops sets situated on Paraíba State, northeast from Brazil.

Material and methods
Study Area -The sampled area (figure 1) in this study includes two rocky outcrops (figure 2 a-b) of the cities of Pocinhos and Puxinanã, in the Campina Grande Microregion, Agreste Mesoregion, Paraíba State, Brazilian northeast.Both cities are identified, from a geomorphologic point of view, as part of the Borborema Plateau (AESA 2014).Pocinhos (07º0514'S -36º0356'W) and Puxinanã (07º08'62.1S,35º58'31.4W)are located at a varying altitude of 600 to 700 m.Pocinhos with annual maximum temperature of 30 ºC and minimum of 21 ºC, and highest precipitation period in March and June (Andrade et al. 2007) and Puxinanã with maximum registered temperature of 28 ºC and minimum of 16 ºC, with precipitation periods from January, March to July, and August (Tölke et al. 2011).
In general, Paraíba's Agreste Mesoregion is phytophysiognomic characterized as an ecologic transitional area between montane forest (Caatinga enclaves moist forests) and the deciduous spiny vegetation (Caatinga), (having areas with different humidity and dry conditions) presenting parts almost as humid as the coast and others as dry as the backcountry (Pereira et al. 2002).Consequently, according to Köppen-Geiger's classification (Peel et al. 2007), the climate is hot semiarid (Bsh, with average annual rainfall of ca.700 mm and severe water scarcity (Brasil 1972, Pereira et al. 2002).
Field and laboratory procedures -The samples in reproductive state were collected through fortnightly excursions between December/2012 and December/2013.All specimens were deposited at the Herbarium Manuel de Arruda Câmara (ACAM).Specimens housed at EAN (Jayme Coelho de Morais) and JPB (Lauro Pires Xavier) were also analyzed (both herbaria linked to the Federal University of Paraíba (UFPB)).The herbaria acronyms follow Thiers (2014).

Results and Discussion
Bromeliaceae A.Juss., Gen. Pl.: 49-50. 1789.In the study area were recorded ten species distributed in six genera.
Distribution and habitat: Bromelia laciniosa is an endemic species to Brazilian's northeast (Smith & Downs 1979, Forzza et al. 2014) Morphologically it is characterized for having glossy leaves, red bracts of scape and densely lepidote, pedicellate flowers with hypanthium forming a tube, purplish white petals and ellipsoid, robust, berry fruit.

Hohenbergia catingae
Distribution and habitat: Hohenbergia catingae was reported to Paraíba and Bahia States by Smith & Downs (1979).In the studied area, it is found in the rock outcrop of Puxinanã, forming an island along with the species of the Cactaceae, Euphorbiaceae and Marcgraviaceae families.
Distribution and habitat: Hohenbergia horrida is endemic to Northeast Brazil; and recorded to the states of Paraíba and Pernambuco (Smith & Downs 1979, Forzza et al. 2014).In the study area it was found forming extensive outcrop vegetation islands in the municipality of Pocinhos.
Phenology: Found flowered in February.
Distribution and habitat: Neoglaziovia variegata is endemic to Brazil and distributed in the Caatinga of northeastern region and the State of Minas Gerais (Smith & Downs 1979, Forzza et al. 2014).It can be found from the sub-grove of tree caatingas to open environments, in compact and thin soils; being common in crevices of rocky outcrops (Alves et al. 2009).In the study area, it is found forming populations of few individuals under bushes, in the plateau regions in the outcrop of municipality Pocinhos.
Phenology: Collected with flowers in May and fruits in May and October.
Distribution and habitat: Orthophytum disjunctum is endemic to Northeast Brazil (Smith & Downs 1979, Forzza et al. 2014), being quite usual in the constitution of the flora of Bromeliaceae in rocky outcrops (Siqueira-Filho 2004).In the study area, it is found on islands of vegetation on the rock, colonizing flattened surfaces; as it was also recorded by Santos (2009) in a study on the vegetation of rocky outcrops in the Brazilian semiarid region.
Phenology: Found with flowers in April and July.
Distribution and habitat: The species is widely distributed species in South America, occurring from the Northeast to Southern Brazil, extending to Argentina, Bolivia and Paraguay (Fiorato 2009, Coffani-Nunes et al. 2010).In Paraíba State, Tillandsia loliacea was found in the agreste, mountainous forests and caatinga (Pontes & Agra 2006); it is one of the most characteristic epiphytes in the semiarid area.
Phenology: Found fruited in April.
Distribution and habitat: Tillandsia recurvata is widely distributed in tropical America, occurring in southern North America, Central America, Caribbean and South America (Pontes 2005).The species is native to Brazil and is distributed in the Northeast, Southeast and South regions (Forzza et al. 2014).
Phenology: Flowered in March and fruited in March and April.
In Paraíba State, T. recurvata has been found in all types of ecosystems (Pontes & Agra 2006).In the study area, it was recorded forming dense clumps and colonizing fruit trees as juazeiro (Ziziphus joazeiro Mart.), umbuzeiro (Spondias tuberosa Arruda) and jaboticabeira (Plinia cauliflora (Mart.)Kausel).This aspect can to corroborate for adaptation of this species to the outcrops, given that, according to Kersten (2010) the species of Tillandsia depend entirely on the moisture and nutrients removed from the air or the bark of phorophytes.
Distribution and habitat: Tillandsia tenuifolia is found in Cuba, Guyana Shield, Venezuela, Bolivia, Brazil, Paraguay and Argentina (Pontes 2005, Fiorato 2009and Coffani-Nunes et al. 2010).In Brazil there are records for almost every state in the northeastern region except Maranhão, Piauí and Rio Grande do Norte States; and all of the Midwest, Southeast and Southregions (Pontes 2005, Fiorato 2009, Forzza et al. 2014).
According to Fiorato (2009)   morphological plasticity, especially in vegetative parts, being recognized five varieties.However, analysis of floral morphology indicates that the set of floral characters is constant.For this reason, such varieties were considered in this work as synonims due to the variations being inaccurate.
It is characterized for having polystichously leaves, usually directed unilaterally bracts along the pinkish scape with apex awned, two connate sepals and one free, connate petals and epipetalous stamens with plicated fillets.Orchidaceae A.Juss., Gen. Pl.: 64-65.1789.
In the study area were recorded six species distributed in five genera.
Distribution and habitat: According to Barros et al. (2014), this species is endemic to Brazil, being recorded in Caatinga, Cerrado and Atlantic Forest in the States of Alagoas, Bahia, Paraíba, Pernambuco and Minas Gerais.In the study area it is found forming carpets on top of the outcrop amid species of the families Apocynaceae, Euphorbiaceae and Bromeliaceae.
Phenology: Found flowered in May and fruited in September.
Acianthera ochreata was originally described by Lindley in 1836 based on a specimen obtained in the Serra Monte Santo, Bahia State, under Pleurothallis ochreata (Azevedo & Van den Berg 2007, Borba & Semir 2001, Borba et al. 2002).However, after a redefinition of the subtribe Pleurothallidinae based on phylogenetic analyses using DNA sequences the species of the genus Pleurothallis were transferred to Acianthera (Pridgeon et al. 2001, Pridgeon & Chase 2003), which was recovered by Luer (2004).
Distribution and habitat: Widely distributed in Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname and Venezuela (Batista et al. 2008).It occurs in vegetation islands on the slope of the outcrop of the municipality of Pocinhos.
Phenology: Flowered in August and fruited in September.
Distribution and habitat: The species occurs in Argentina and the Brazilian East coast of Paraíba to Santa Catarina and Goiás States (Cunha & Forzza 2007, Barros et al. 2014).In the study area was found forming small populations primarily in crevices of rocky located on the edge of central outcrop or composing vegetation islands species of Bromeliaceae and Euphorbiaceae in the municipality of Pocinhos.
It is characterized by having leaves forming a basal rosette and inflorescence with flowers 0.2-0.3cm length, yellowish-green, pedicel with approximately 0.2 cm length and cuculate lip.

Conclusions
This work contributed to the expansion of the knowledge on the taxonomy and representativeness of the families Bromeliaceae and Orchidaceae in rocky environments in the Brazilian northeastern, especially to the State of Paraiba, besides to provide data for conduct studies on different aspects of such families and data for the implementation of conservation policies of the flora associated to rocky environments of Paraíba State.

Figure 1 .
Figure 1.In the first plane (anti-clockwise), the location of the municipalities of Pocinhos and Puxinanã in the Paraíba State, Brazil; in the second and third plane, the location of the studied areas.

the study area, B. laciniosa was found under trees and in clearings formed between bushes at the edge of rocky outcrops in the city of Puxinanã. Phenology: Flowered in March and May, and fruited in May.
, there are approximately 2,450 species allocated in 240 genera in the Brazilian territory, covering about 1,640 endemic species.For Paraíba State, 57 accepted names are recorded in a total of 593 species for the northeast region.Of the six species of Orchidaceae recorded in the study area, five were found in Pocinhos and three in Puxinanã; with one species Cyrtopodium holstii L.C. Menezes common to both sets of rocky outcrops studied (table 1).Key to the Orchidaceae species from rocky outcrops of the cities of Pocinhos and Puxinanã Habenaria obtusa 3. Plants without globose tuberoids; leaves polystichous; floral bracts not imbricate; pedicel ca.0.2 cm length, not calcarate flowers, oblong dorsal sepal; lip cuculate .......................
, this species is endemic to Brazil, having as synonymous Cyrtopodium inaldianum L.C. Menezes.It was recorded for most states in the Northeast, States of Pará (North), Espírito Santo and Minas Gerais (Southeast), being associated with areas of Caatinga, Atlantic Forest and Amazon Rainforest.It was found in the rocky outcrops of Pocinhos.Cyrtopodium holstii is morphologically related to C. flavum, also recorded in this study (see comments on C. flavum).However, it can be distinguished of this later for having sepals and petals with red stains and crisped margin, lip with lateral lobes of entire margin and central lobe margin crisped.