Barriguda / Paineira-rosa flower / Cotton-silk-tree (Ceiba speciosa) Park Ceret Sao Paulo. Brazilian tree

The silk floss tree (Ceiba speciosa, formerly Chorisia speciosa), is a species of deciduous tree native to the tropical and subtropical forests of South America. It has a host of local common names, such as palo borracho (in Spanish literally "drunken stick"). It belongs to the same family as the baobab and the kapok. Another tree of the Ceiba genus, C. chodatii, often receives the same common names.

The natural habitat of the floss silk tree is the north-east of Argentina, Paraguay, Uruguay and southern Brazil. It is resistant to drought and moderate cold. It grows fast in spurts when water is abundant, and sometimes reaches more than 25 metres (82 ft) in height. Its trunk is bottle-shaped, generally bulging in its lower third, measuring up to 2 metres (7 ft) in girth. It is studded with thick conical prickles which serve to store water for dry times. In younger trees, the trunk is green due to its high chlorophyll content, which makes it capable of performing photosynthesis when leaves are absent; with age it turns to gray.

The branches tend to be horizontal and are also covered with prickles. The leaves are composed of five to seven long leaflets.

Ceiba is the name of a genus of many species of large trees found in tropical areas, including Mexico, Central America, South America, The Bahamas, Belize and the Caribbean, West Africa, and Southeast Asia. Some species can grow to 70 m (230 ft) tall or more, with a straight, largely branchless trunk that culminates in a huge, spreading canopy, and buttress roots that can be taller than a grown person. The best-known, and most widely cultivated, species is Kapok, Ceiba pentandra.

Recent botanical opinion incorporates Chorisia within Ceiba, raising the number of species from 10 to 20 or more, and puts the genus as a whole within the family Malvaceae.

Ceiba species are used as food plants by the larvae of some Lepidoptera (butterfly and moth) species including the leaf-miner Bucculatrix ceibae which feeds exclusively on the genus.

Bombacaceae is a family of flowering plants or Angiospermae included within Malvales order. As is true for any botanical name, circumscription and status of the taxon has varied with taxonomic point of view. The family name is based on the genus Bombax.

Recent phylogenetic research has shown that Bombacaceae as traditionally circumscribed (including tribe Durioneae) is not a monophyletic group. Bombacaceae is not recognized by the Angiosperm Phylogeny Group I 1998, II 2003 and Kubitzki system 2003 at the rank of family, the bulk of the taxa in question being treated as subfamily Bombacoideae within family Malvaceae sensu lato. A close relationship between Bombacaceae and Malvaceae has long been recognized but until recently the families have been kept separate in most classification systems, and continue to be separated in many references, including the reference work in classification of flowering plants: Heywood et al. 2007 and Takhtajan 2009, but have been lumped together in Angiosperm Phylogeny Website.

Heywood et al. say "although closely related to Malvaceae, molecular data supports their separation. Only pollen and habit seem to provide a morphological basis for the separation." On the other hand they say: "One approach is to lump them [the families in the core Malvales, including Bombacaceae] all into a 'super' Malvaceae, recognizing them as subfamilies. The other, taken here, is to recognize each of these ten groups as families."