Levantamento florístico das angiospermas do Parque Estadual Cânion do rio Poti, Buriti dos Montes – PI

O Parque Estadual Cânion do Rio Poti (24.772,23 ha), localizado no municipio de Buriti dos Montes, e uma importante Unidade de Conservacao e Protecao Ambiental no Estado do Piaui. Assim, objetivou-se identificar as especies de angiospermas ocorrentes na area de afloramentos rochosos no Parque Estadual Cânion do Rio Poti, Buriti dos Montes. A coleta, herborizacao, identificacao e classificacao das especies seguiu a literatura usual especializada. Os especimes encontram-se depositadas no Herbario Prof. Aylthon Brandao Joly do Centro de Estudos Superiores de Caxias, CESC/UEMA. A flora de angiospermas do Parque e composta por 96 especies, distribuidas em 82 generos e 34 familias. Destas, 85,4% (82 spp.) sao eudicotiledoneas e 14,6% (14 spp.) sao monocotiledoneas. As familias mais ricas em especies foram Fabaceae (21 spp.), Apocynaceae e Cactaceae (6 spp.); Bignoniaceae e Euphorbiaceae (5spp); Araceae, Anarcadiaceae, Boraginaceae, Cyperaceae  e Malvaceae (4 spp.); Bromeliaceae e Rubiaceae (3 spp.), que juntas totalizaram 71,9%, enquanto que as demais apresentaram entre uma a duas especies (28,1%). Para a area de estudo 9,3% (9 spp.) sao novos registros para o Piaui, Ancistrotropis peduncularis (Kunth) A. Delgado, Astrocaryum vulgare Mart., Cryptostegia madagascariensis Bojer, Cordia oncocalyx Allemao, Ipomoea piurensis O'Donell, Matelea ganglinosa (Vell.) Rapini, Simaba guianensis, Vitex gardneriana Schaue e Waltheria operculata Rose; 11,5% (11 spp . ) sao endemicas para a Caatinga e 3,1% (3 spp) sao novos registros para a Caatinga. Este e o primeiro estudo floristico para o municipio, que contribui com informacoes importantes para a area de afloramentos rochosos com ampliacao da ocorrencia e a distribuicao geografica das especies no Brasil. Floristic survey of the angiosperms of the State Park Canon of the Poti river, Buriti dos Montes - PI A B S T R A C T The The Poti River Canyon State Park (24,772.23 ha), located in the municipality of Buriti dos Montes, is an important Conservation and Environmental Protection Unity in the State of Piaui. Therefore, this research purpose was to identify the angiosperms species which occurr in rocky outcrops in the aforementioned Park. The collection, herborization, identification and classification of specimens was followed the usual specialized literature. The specimens are deposited in the Herbarium Prof. Aylthon Brandao Joly, located on the Center for Superior Studies of Caxias, CESC / UEMA. The park's angiosperm flora is composed by the 96 species, distributed in 82 genera and 34 families. Among these, 85.4% (82 spp.) are eudicotiledonous and 14.6% (14 spp.) are monocotyledonous. The richest families in number of species were Fabaceae (21 spp.), Apocynaceae and Cactaceae (6 spp.); Bignoniaceae and Euphorbiaceae (5spp); Araceae, Anarcadiaceae, Boraginaceae, Cyperaceae and Malvaceae (4 spp.); Bromeliaceae and Rubiaceae (3 spp.), which together had a total of 71.9% of the species, while the others presented between one and two species (28.1%). For this study area, 8.3% (8 spp.) was the firts records for Piaui state, they are Astrocaryum vulgare Mart., Cyperus pohlii (Ness) Steud., Cryptostegia madagascariensis Bojer, Cordia oncocalyx Allemao, Ibatia ganglinosa (Vell.) Morillo, Piptadenia retusa P.G.Ribeiro, Seigler & Ebinger , Vitex gardneriana Schaue e Waltheria operculata Rose as its representants. 14,6% (14 spp.)  are endemic to the Caatinga and 5,2% (5 spp.) are new species records for it. This is the first floristic study for the municipality, which contributes with important information to the area of rocky outcrops, increasing the occurrence and the geographic distribution of the species in Brazil. Keywords: Caatinga. Plant diversity. Floristic list. Semi-arid.