Floristic survey of ornamental plants used in Dom Delgado University City at the Universidade Federal do Maranhão , São Luís , Maranhão State , Brazil

The objective of this study is to list the flora used in ornamentation, afforestation and landscaping in the common areas of the Dom Delgado Campus (São Luís) at the Universidade Federal do Maranhão (2o32’20.7”S 44o16’58.4”W), where this study was carried out. The collection took place through exploratory walks, including individual specimens planted there and those that were kept during the architectonical development of the University. Identification was obtained using analytical keys, specialized literature and the comparison with material previously identified in the Herbarium of Maranhão (MAR) where the exsiccates produced in the present study were deposited. 70 species, 56 genres and 29 families were found. Fabaceae (with 10 species), Apocynaceae (with nine spp.); Malvaceae and Rubiaceae (six spp.); Arecaceae (four spp.); Araceae, Bignoniaceae and Heliconiaceae with three species each were the most representative families in terms of the number of species. Among the total number of species identified, it was noted that there was no great difference in the quantity of native Brazilian species (38%), when compared to exotic species (34%); the remaining species were classified as cultivated (17%) and naturalized (11%). In conclusion, it is clear that the afforestation/ landscaping of the Dom Delgado Campus, follows a method of randomization in relation to the planting of the species used.


INTRODUCTION
Vegetation, with its ecological, economic and social functions, can play an important role in the life of urban populations.However, much of the plant community is subject to processes of landscape cleanup and environmental destruction.In this sense, a degradation of the natural landscapes is assuming unsustainable proportions, in relation to the loss of the native vegetation and the quality of the ecosystems before the increase of the number of cultivated and exotic plants (PAIVA et al., 2004).
However, plants grown in a city, both for ornamentation and afforestation, bring benefits ranging from a reduction of the islands of heat (LOMBARDO, 1985), to the increase of human well-being (GRAHN and STIGSDOTTER, 2010), also offering a support for housing, rest and nesting of urban fauna (MENEZES, 2004).Nowadays, an association between an afforestation / urban landscape and a quality of life of its inhabitants is undeniable (MILANO, 1995).In this context, ornamental plants are those that attract attention and arouse interests by their aesthetic characteristics such as color, leaf form and flowers, phenological aspects, projected shadow, the swing caused by the wind and still by the visual structure formed with the plants nearby (SILVA, 2009).Trees may also be considered ornamental species, when they are planted to promote the beautification of the environment, adjusting to the free spaces, establishing a man-nature contact (SILVA, 2009).
In Brazil, plants that are used for ornamentation in landscaped environments are generally exotic and with little known phenology, whose planting has become exclusively due to unknowledge of the species (LORENZI and SOUZA, 2001).While they serve to enhance a scenic beauty of urban environments, these plants can pose problems when choices and plantings are inadequately.In most cases, the plants are selected only by analyzing their aesthetic traits, not considering important characteristics such as location of origin (HEIDEN et al., 2006), stem shape, crown shape, propagation velocity and growth (ZILLER, 2006).In this way, the practice of improving the scenic landscape requires knowledge of botany, ecology, regional climatic variations and architectural styles, as well as the study of plastic compatibilities for the balance of forms and colors (MARX and TABACOW, 2004).
In the urban arborization, are inserted the spaces of the Universities that are peculiar for the capacity to produce science and human resources, being able to become a space for floristic projects that consider the different aspects in the use of vegetal species, being these either native or exotic (EISENLOHR et al., 2008).This potential is evidenced by the floristic records developed by Paiva et al. (2004), Kurihara et al. (2005), Castro et al. (2011), Brianezi et al. (2013), in different Universities of Brazil.
Thus, the purpose of this study is to list the flora used in ornamentation, afforestation and landscaping in the common areas of Dom Delgado University City at the Universidade Federal do Maranhão.

MATERIAL AND METHODS
The collections of the species were carried out in the flowerbed, parking lots, main and secondary roads, gardens, interior and between the open areas of the buildings (Figure 1) of Dom Delgado University City (2º32'20.7 "S 44º16'58.4"W) at the Universidade Federal do Maranhão -UFMA (Figure 2), located in the municipality of São Luís, whose area has about 0.969 km².The region has Aw type climate (KÖPPEN, 1948), tropical rainy, with predominance of rainfall in the months of January to June.The study was developed from August 2016 to August 2017 by means of exploratory walks, collecting the individuals planted and those who were kept to shade and / or beautify the campus along the architectural development of the University.All specimens in the reproductive stage were collected, photographed and herborized according to the usual botanical methodologies (MORI et al., 1989;PEIXOTO and MAIA, 2013).Identifications were carried out with the help of analytical keys, specialized literature and by means of a comparison with material already identified in the Herbarium of Maranhão (MAR), Department of Biology, Universidade Federal do Maranhão (ALMEIDA JR. et al., 2015).The exsiccates produced in the present study were deposited in the Herbarium MAR.
Where possible, the origin, habit, endemism and vernacular names associated with the species were also investigated.
The most representative families in number of species were Fabaceae with 10 species, Apocynaceae (eight spp.);Arecaceae and Malvaceae (five spp., each); Rubiaceae (four spp.);Araceae, Bignoniaceae and Heliconiaceae with three species, each.The greater representativeness of the families Fabaceae and Apocynaceae was also observed in works developed by Kurihara et al. (2005) at the Universidade de Brasília; Eisenlohr et al. (2008) and Brianezi et al. (2013) both at the Universidade Federal de Viçosa.
There was a predominance of two families: Fabaceae, one of the largest families of angiosperms with cosmopolitan distribution and one of the main economically.The species of this family are always used in ornamentation and urban afforestation in Brazil, besides having species that produce quality wood (SOUZA and LORENZI, 2005).The Apocynaceae family also stands out for having pantropical distribution.Many species of this family are cultivated as ornamental, but several are toxic to humans and, for this reason, are not totally appropriate for cultivation in certain areas (SOUZA and LORENZI, 2005).Although toxic, species are used as ornamental.Therefore some care must be taken with the choice of spaces where these plants are placed in order to avoid direct contact with the population.
From the total number of species identified, there is no significant difference between the number of exotic species (34%) and native species in Brazil (40%).Cultures (15%) and naturalized (11%), although used, had little representativeness for the present study.Similar results were found by Carvalho et al. (2007)  In the study by Eisenlohr et al. (2008), also in the Universidade Federal de Viçosa, the predominance of exotic species was higher than the native ones, showing that although there is a greater number of native species in many works, the choice for exotic plants still stands out, being a factor that must be considered in urban afforestation and landscaping projects.It is necessary to give preference to the autóctones species, that is, those that are native to the natural ecosystems of each region where the city is located, as these would benefit urban ecosystems (CASTRO et al., 2011).
It is evidenced that the arborization/landscaping of Dom Delgado University City, apparently, does not follow a planned landscape line due to the lack of organization V. 23, N o .4, 2017, p. 451-459 of the aesthetic characters in relation to the plants chosen (Figure 3), being perceived the "randomization" of the planting of the species used.Thus, the present study may serve as a basis for a management plan for more consistent ornamentation, following a clear, efficient and didactic proposal (LEAL et al., 2009), and in the future replace the species considered inadequate for planting in Maranhão.

CONCLUSIONS
It can be concluded that the data of the present study could contribute in the elaboration of a more efficient afforestation and ornamentation plan to contribute to the "beautification" of the common areas Dom Delgado University giving priority to native species in the face of scenic beauty.In addition, it can help in future works that aim at the use of plants more suitable for the region, prioritizing the native species to the detriment of the exotic species; investing in the reproduction of the native species to replace or isolate of the exotic species.

CONTRIBUTIONS OF AUTHORS
LBSC: Bibliographic review, data collection, species identification, data analysis and interpretation, manuscript preparation.CSP: Bibliographic review, data collection, species identification, data analysis and interpretation, manuscript preparation and technical activities.JSA: Bibliographic review, data collection, species identification, data analysis and interpretation, manuscript preparation and technical activities.BEFC: Data collection, species identification, data analysis and interpretation, manuscript review.EBAJ: Conception of the study, critical review of the results, approval of the final version of the manuscript.
at the Universidade Federal da Bahia; Potascheff et al. (2012) at the Universidade Estadual Paulista Júlio de Mesquita and by Brianezi et al. (2013) at the Universidade Federal de Viçosa.