Reinterpretation of the nomenclatural type of Pseudobombax heteromorphum (Malvaceae, Bombacoideae) reveals new species from Bolivia

Posted October 20, 2017

Pseudobombax has been shown to be associated with the development of the pseudobombax,

Photograph of an isotype of Pseudobombax pulchellum Carv.-Sobr. Gentry et al.75227, F 2111431).

Distribution of > Pseudobombax pulchellum Carv.-Sobr. in Santa Cruz, Bolivia. Dashed lines indicate the boundaries of the Kaa-Iya of the Gran Chaco National Park.

Pseudobombax pulchellum is a remarkable species by its diminutive aspect, especially the relatively small, retreat, the petiolules are markedly long in relation to the petiole, and fruits are conspicuously acuminate. It seems to be closely related to Pseudobombax longiflorum (Mart.) A. Robyns, a sympatric congener in Bolivian Chiquitano dry forest. The two are similar because of their glabrous aspect, long petiolules, leaflets with retuse apices, truncate to cordate bases, and maculate seeds.

Pseudobombax croizatii < / em> Carb.-Sobr. & amp; L.P. Queiroz; both of these species share small flowers (60-65 mm long), glabrous staminal tubes, androecia with relatively few stamens (c.150-200), and glabrous fruits. The following key can be used to separate these four species of Pseudobombax.

1

Petiolules 14-75 mm long. Petals externally blackish, staminal tube lacking phalanges (filaments freely originating from the apex of the tube). Seeds bicolored, maculate

2

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Petiolules to 5 mm long. Petals externally cream-colored, staminal tube originating phalanges 3-5 mm long. Seeds uniformly colored

2

Pseudobombax pulchellum (Bolivia)

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Petioles 6-12 times the length of the petiolules. Flowers 15-22 mm long, calyx 15-25 mm long, staminal tube 35-60 mm long. Capsules 14-24 mm long, acuminate for the distal 3% -5% of their length

Pseudobombax longiflorum (Bolivia, Brazil, Paraguay, Peru )

3

Leaflets 7-9, obovate, cuneate, margins revolute. Flowers to 60 mm long, staminal tube glabrous. Capsules 55 mm long, not acuminate

Pseudobombax minimum 5, elliptic to broad-elliptic, acute, margins plane. Flowers 85-100 mm long, staminal tube with bands of simple trichomes. Capsules c. Pseudobombax croizatii