Philodendron williamsii Hook . f . ( Araceae ) , an endemic and vulnerable species of southern Bahia , Brazil used for local population

1,3 Universidade Federal do Rio de Janeiro, CCS, Instituto de Biologia, Departamento de Botânica, Av. Carlos Chagas Filho, 373 Sala A1-084 Bloco A, CEP 21941-902, Ilha do Fundão, Rio de Janeiro, RJ, Brazil 2 Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Botânica, Quinta da Boa Vista, CEP 20940-040, Rio de Janeiro, RJ, Brazil Emails: 1 luanasbcalazans@gmail.com (corresponding author), 2 ericcabarroso@gmail.com, 3 cmsakura12@gmail.com

Philodendron williamsii Hook.f. is a poorly known species of Philodendron subgenus Meconostigma (Araceae), described in 1871 from material collected by C.H. Williams in the Bahia State, probably near Salvador and has been cultivated at Kew (Mayo 1991).
Due to some similar morphological characters with P. stenolobum E.G. Gonç.(Gonçalves & Salviani 2002), many horticulturists believe they have it in their collections, however, they actually possess specimens of the latter.Populations currently circumscribed as P. stenolobum, which is endemic to the Espírito Santo state, were treated as P. williamsii in the latest revision of the subgenus Meconostigma (Mayo 1991), since the author could not have access to the fertile material from these populations.The main differences between them lie in leaf dimensions and gynoecium morphology (Table 1 in Gonçalves & Salviani 2002).Despite its ornamental potential for landscaping, P. williamsii is rarely found in live collections due to the difficulty of its propagation and cultivation.
The aim of the work is to give new information on ecology, geographical distribution, uses, ethnobiology and conservation of P. williamsii, an endemic and threatened species from the Atlantic Forests of southern Bahia.

Materials and Methods
Field work was carried out in February and December of 2011, searching for Philodendron species in Bahia State, specially prospecting areas of Itacaré and Una, where the species grows.Special effort was made to collect the plants during the fertile period.In order to obtain information on its use by the local population, semi-structured interviews were conducted (Huntington 2000), selecting informants (craftsmen, merchants and foresters) who use parts of the plants directly in their activities.
To complement the description, ecological data and geographical distribution, material from the following herbaria were also analyzed: ALCB, CEPEC, HUEFS, RB, RFA according to Thiers, constantly updated).The descriptions followed Mayo (1991), with modifications.The conservation status was proposed based on the categories and the criteria proposed by the IUCN (2010).

Ecology and Distribution
Philodendron williamsii has a distribution restricted to the Atlantic Forest on the southern coast of the Brazilian state of Bahia, where part of the original vegetation remains protected due to ecotourism (Oliveira 2002) and cocoa cultivation, which is the major crop of the region (Cassano et al. 2009;CEPLAC 2011).Although its type locality is pointed probably near Salvador, there are no for the region and vicinity and we did not see any population around the city.This species can be considered rare in nature since there are few herbarium collections and a limited area of occurrence (Fig. 1).
It occurs in the restingas and pluvial forest, including flooded areas, as hemi-epiphytes, rupicolous or terrestrial.Generally, populations are not too close.They were always under median to high luminosity, as commonly noted in the Philodendron subg.Meconostigma.Terrestrial individuals are generally found in forest edges, clearings or sandy soils of restinga vegetation.Hemi-epiphytes are more common and can reach a great height in the canopy (up to 25m), where the light intensity is higher.This feature makes these hemi-epiphytes individuals hard to be noticed and collected, as reported by many collectors.However, once found, it can be promptly recognized by the long feeder roots that reach the ground, sometimes growing several meters until finally entering the soil (Image 2b).
There is a remarkable population growing on granitic outcrops rocks at Itacaré beach, a few meters from the sea (Image 1a&d).This same population was previously related as a form of P. corcovadense Kunth with shorter internodes (Mayo 1991), but we were able to collect their flowers and fruits and verify they belong to P. williamsii.These species are morphologically similar and frequently grow in similar conditions, both being endemic to the Brazilian Atlantic coast.The main differences between them are in stem and gynoecium morphology (longer internodes, conspicuous intravaginal squamules, ovary barrel-shaped, 4-8-locules and style lobes short in P. corcovadense).Mayo (1991) reported that P. williamsii fruits were appreciated as a native delicacy, called "milho de caboclo" (caboclo's corn), but despite our efforts, we couldn't confirm if this use by the local population still occurs.

Uses and Ethnobiology
The roots are widely used in local craftwork.The handicraftsmen refer to the young roots of P. williamsii as "imbé" and take the outer layer (storied cork) (Image 2c) to ornament their pieces, such as lampshades, luminaries and trays (Image 2d).These layers are very slender and translucid, allowing the passage of red-colored light, which adds a special beauty to the pieces, making it unique and characteristic of this area in Bahia.The mature roots are grey and opaque but possess some brightness and are also used to make handcrafted, rustic pieces.
The entire plant is called "mãe do imbé" (imbé's mother) and the leaf scars in the stem are called "olhos do imbé" (imbé's eyes) (Image 2a) due to its appearance.The craftsmen are easily able to distinguish the Philodendron species that occur in the region, almost entirely, based on their use.Thus, P. fragrantissimum (Hook) G. Don., a common species in the region, is called "mother", but is a mother that never gives "imbé".Philodendron pedatum (Hook.)Kunth and P. hederaceum (Jacq.)Schott are not recognized as "mothers", probably because their morphology differs from much of P. williamsii.
Another folk belief is that P. williamsii plants are always born on the tree branches and when the "mother" is mature, the "imbé" (roots) drop to the ground.This may be partly explained due to the difficulty to find young terrestrial individuals, probably due to light conditions on forest soil.
Although the craftsmen who accompanied us said that only few roots are taken off each individual, this activity must be carefully monitored since it is very common in southern Bahia and puts these populations at risk.The local population knows by tradition that just after a year the roots are ready again to be extracted, but they are not aware that the plant might die if the roots are completely removed.This shows that tradition and popular knowledge doesn't always assure the protection of this species.
The roots of two others Philodendron subg.Meconostigma species that occur in the Atlantic Forest, P. bipinnatifidum Schott ex Endl.and P. corcovadense, respectively in São Paulo and Paraná states, are also used by the local population to create craft items and other rural constructions (Schneider & Mello Filho 2001;Valente & Negrelle 2011).In the Amazonian region, various species of the genus Heteropsis Kunth are also used for this purpose (Soares et al. 2011).

Conservation
In view of its rarity and anthropic pressure, we propose the species be assessed for inclusion in the IUCN Red List of Threatened Species providing support for its conservation.We believe that the regularization of extractive activity and environmental education is important and will allow the continued use of P. williamsii in craftwork without affecting their natural populations.This species is known only in a small area in southern Bahia (< 20000km²), mainly in the moist forests, occurring at least in three conservation units, with very few known populations.
Due to its ecological features and ethnobiology, this plant has become increasingly difficult to find in the past few years.To help assure the continuation of this traditional activity, studies on its propagation in vitro and acclimatization would also be desired.

Figure 1 .
Figure 1.Geographic distribution of Philodendron williamsii.Red points are our collections (Calazans & Morais 54 and Calazans et al. 139,155) and black points are other collections from the analyzed Herbaria.