Levantamento de plantas conhecidas como mututi, com ênfase ao estudo morfológico de espécies de pterocarpus jacq. (leguminosae)

Abstract

Some wood-producing species are popularly known as "mututi" and occur in several regions of Brazil, mainly in the Amazon. The use of only the popular nomenclature can cause serious problems from the point of view of the quality of the commercialized product and the conservation of the species, especially when different species are grouped together. The present work aimed to carry out a survey of the species known as "mututi", starting the morphological study by those belonging to the genus Pterocarpus lacq. The survey was carried out in the literature and in the databases of the herbaria of the state of Pará (lAN and MG). The nomenclature of the species found in this survey was researched in the specific literature in order to know the accepted names and synonyms. Field observations were made and botanical samples were collected from three species of Pterocarpus in some municipalities of Pará. From each plant, five branch samples were collected, measuring about 30 to 40 cm in length, with mature leaves, flowers and/or fruits. The samples were dehydrated in an electric oven and the flowers were preserved in 70% alcohol for later analysis. Adult structures (length of leaves, rachis and petiole, length and width of leaflets, petioles and fruits) were measured using a millimeter ruler. For analysis and measurement of floral elements, flowers were dissected and analyzed under a stereomicroscope, from material preserved in liquid medium or rehydrated material. The identification of the collected material was carried out in the collection of the IAN herbarium, by comparison with specimens previously identified by specialists, and consultation of specialized literature. Nineteen species known as mututi were found, of which six are currently considered synonyms; all belong to the Leguminosae-Papilionoideae, but to seven different genera: Bocoa (1 species), Etaballia (1), Lonchocarpus (1), Paramachaerium (2), Platymiscium (1), Pterocarpus (4) and Swartzia (4 species). The morphological study started with the genus Pterocarpus, and three species were analyzed: Pterocarpus officinalis Jacq. ssp. officinalis, P. rohrii Vahl. and P. santalinoides L? Hér. ex De. The diagnostic characters of greatest relevance for distinguishing the species were the type of inflorescence, location of indumentum on the ovary and the consistency of the wing and size of the fruits. Pterocarpus officinalis has paniculate inflorescence, stipitate ovary with trichomes only at the suture and fruit measuring 2.8-4.9 cm x 3-5.2 cm, with leathery wing. Pterocarpus rohriitem racemose inflorescence, rarely paniculate, sessile ovary all covered with trichomes and fruit measuring 4-9 cm x 3.5-7.5 cm, with membranaceous wing. Pterocarpus santalinoides has a racemose inflorescence, sessile ovary all covered with trichomes and fruit measuring 1.5-4 cm x 1-4 cm, with a leathery wing.