Waltillia Leme, Barfuss & Halbritter, 2017

Leme, Elton M. C., Halbritter, Heidemarie & Barfuss, Michael H. J., 2017, Waltillia, a new monotypic genus in Tillandsioideae (Bromeliaceae) arises from a rediscovered, allegedly extinct species from Brazil, Phytotaxa 299 (1), pp. 1-35 : 29

Waltillia Leme, Barfuss & Halbritter , gen. nov.

Diagnosis:—This new genus differs from Alcantarea , Stigmatodon , and Vriesea by its unique combination of morphological characters, such as unappendaged petals 4 to 6 times longer than wide, forming a narrow campanulate corolla, pollen with the sulcus margins more or less well defined but not sharply cut, the sulcus covered with a kind of operculum of almost smooth exine elements with some perforations, stigma of the convolute-blade II type, and seeds with a basal appendage equalling to distinctly shorter than the apical appendage.

Type:— Vriesea hatschbachii L. B. Sm. & R. W. Read.

Description:— Plants terrestrial (including saxicolous) growing along the margins of running streams or in periodically soaked terrains. Leaves coriaceous, forming non-impounding rosettes; leaf blades sublinear, long-attenuate. Inflorescence usually simple or sometimes compound. Flowers distichous, downward secund at anthesis, nocturnal, weakly scented; petals free, 4 to 6 times longer than wide, recurved at anthesis and forming a narrow campanulate corolla, becoming erect again afterwards, unappendaged; filaments free, slightly complanate; anthers with the pollen sacs with a prevailingly frontal line of dehiscence, connective area completely exposed and not covered by the margins of the pollen sacs at anthesis; pollen with elliptic outline, ca. 70 μm in diameter, sulcate, the sulcus with moderately to weakly defined margins, covered with a kind of operculum of almost smooth exine elements with some perforations; ovary 1/4 to 1/3 inferior (considering the nectary), placentation totally superior; ovules caudate; stigma of the convolute-blade II type, green. Fruits a septicidal capsule; seeds with the umbrella-like, plumose basal coma equalling to distinctly shorter than the straight, undivided, well developed apical appendage.

Species:— Waltillia is a monotypic genus.

Etymology: —This new genus honors the botanist Walter Till, Curator of the Herbarium of the Department of Botany and Biodiversity Research, University of Vienna, leading authority in Bromeliaceae in general, and in subfamily Tillandsioideae in especial.

Distinctive characters:— Waltillia is a member of tribe Vrieseeae , subtribe Vrieseinae , being closely related to Alcantarea , Stigmatodon and Vriesea (see results section above and table 2). However, this new genus differs from Alcantarea by petals 4 to 6 times longer than wide (vs. 10 to 15 times longer than wide), forming a narrow campanulate corolla (vs. corolla not campanulate), remaining persistent and becoming erect after anthesis (vs. ephemeral and flaccidescent after anthesis), unappendaged (vs. bearing well developed basal appendages); pollen sacs of the anthers with the line of dehiscence prevailingly frontal (vs. prevailingly lateral), leaving the connective area completely exposed and not covered by the margins of the pollen sacs at anthesis (vs. the opposed margins of the pollen sacs becoming strongly recurved and touching each other and completely covering the connective area at anthesis), pollen with sulcus margins more or less well defined but not sharply cut (vs. margins sharply cut), sulcus covered by a kind of operculum of almost smooth exine elements with some perforations (vs. sulcus without any or bearing only small and low ornamental elements), and stigma of the convolute-blade II type (vs. conduplicate-erect or conduplicate-patent types).

In relation to Stigmatodon , it differs by having the leaf blades sublinear-attenuate, strongly canaliculate (vs. often triangular-acuminate, weakly if at all canaliculate), petals unappendaged (vs. bearing well developed basal appendages), stigma of the convolute-blade II type, densely papillose (vs. tubo-laciniate type, without papillae or rarely sparsely papillose), pollen with the sulcus covered by a kind of operculum of almost smooth exine elements with some perforation (vs. the sulcus covered by exine elements separated from each other, forming isolated exine islands), seeds with a basal appendage equalling to distinctly shorter than the apical appendage (vs. basal appendage distinctly longer than the seed proper and a short apical appendage).

In comparison with Vriesea , it differs by having the leaf rosette with no or rudimentary water-holding capacity (vs. leaf rosette with distinct water-holding capacity), petals unappendaged (vs. bearing well developed basal appendages), pollen with the sulcus covered by a kind of operculum of almost smooth exine elements with some perforation (vs. the sulcus covered by exine elements separated from each other, forming isolated exine islands), and seeds with a basal appendage equalling to distinctly shorter than the apical appendage (vs. basal appendage well developed and many times longer than the inconspicuous apical appendage).