Sp. Pl. 1: 286. 1753; Gen. Pl. ed. 5; 138, 1754.
Herbs, usually epiphytic, stemless to long caulescent. Leaves mostly many-ranked, rosulate, or occasionally 2-ranked and/or laxly arranged; blade linear to triangular or ligulate, margins entire, trichomes usually conspicuous. Inflorescences central, 1–many-flowered, 2-ranked; floral bracts mostly broad, conspicuous, rachis covered or exposed at anthesis. Flowers bisexual; sepals distinct or adaxial pair connate, usually symmetric; petals distinct; stamens included or exserted, filaments free; ovary superior. Capsules cylindric, dehiscent. Seeds with basal, white, plumose appendage.
Widespread in the Neotropics.
Species ca. 550 (13 species and 2 described natural hybrids in the flora).
|1||Leaves 2-ranked; inflorescence 1–2(–3)-flowered.||> 2|
|1||Leaves many-ranked; inflorescence more than 3-flowered.||> 3|
|2||Stems elongate, plants forming pendent festoons; inflorescence reduced to single, apparently sessile flower, scape concealed within leaf sheath; petals yellow-green||Tillandsia usneoides|
|2||Stems short, plants densely clustered to form spheric masses; inflorescence of (1–)2(–3) flowers, scape conspicuous; petals violet||Tillandsia recurvata|
|3||Floral bracts spreading and/or small, exposing most of rachis at anthesis.||> 4|
|3||Floral bracts imbricate, broad, covering all or most of rachis, rachis not visible at anthesis.||> 5|
|4||Leaves 10–20, spirally twisted, banded silver; floral bracts 2.3–3.1 cm; inflorescences with 2–6 flowers per branch; corolla pink to dark rose||Tillandsia flexuosa|
|4||Leaves greater than 20 in number, not twisted or banded (rarely variegated with linear cream stripes); floral bracts 1.2–2 cm; inflorescence with 6–11 flowers per branch; corolla white||Tillandsia utriculata|
|5||Leaf sheath conspicuously inflated; plants pseudobulbous.||> 6|
|5||Leaf sheath flat or only slightly inflated; plants not pseudobulbous.||> 10|
|6||Leaf blade channeled to involute; scapes 8–35 cm; floral bracts glabrous to inconspicuously scaly near apex only.||> 7|
|6||Leaf blade involute; scapes 1–15 cm; floral bracts densely scaly.||> 8|
|7||Leaf blade and scape bracts twisted, reflexed||Tillandsia balbisiana|
|7||Leaf blade and scape bracts erect to spreading||Tillandsia x smalliana|
|8||Scape 7–15 cm; plants from extreme s Texas||Tillandsia baileyi|
|8||Scape 6 cm or less; plants from Florida.||> 9|
|9||Inflorescence linear to narrowly elliptic; base of floral bracts visible at anthesis||Tillandsia paucifolia|
|9||Inflorescence broadly elliptic; base of floral bracts not visible at anthesis||Tillandsia pruinosa|
|10||Leaf blade obviously narrowly triangular, tapering evenly from base to apex.||> 11|
|10||Leaf blade linear-triangular to filiform.||> 12|
|11||Leaves soft, brittle; inflorescence simple or laxly 2–3 branched, never palmate; floral bracts 0.6–0.9 cm wide||Tillandsia variabilis|
|11||Leaves stiff, leathery; inflorescence densely palmate to laxly 2(–3)-pinnate with 3–15 branches; floral bracts 1.2–2 cm wide||Tillandsia fasciculata|
|12||Leaf sheath narrowly elliptic, 1.2–2 cm wide, slightly inflated||Tillandsia simulata|
|12||Leaf sheath broadly elliptic to triangular, 0.8–2.5 cm wide, flat.||> 13|
|13||Leaves finely appressed-scaly, appearing green to reddish green; sheath of scape bracts, especially distal ones, narrowing abruptly into blade; floral bracts green or tinged red, uniformly scaly; corolla lavender||Tillandsia setacea|
|13||Leaves densely and coarsely appressed-scaly, appearing gray; sheath of scape bracts narrowing gradually into blade; floral bracts uniformly red to rose, scaly distally, becoming sparsely scaly toward base; corolla violet.||> 14|
|14||Leaves 15–30, not over 0.5 cm wide at mid-length; inflorescence simple or with 1–5 lateral branches||Tillandsia bartramii|
|14||Leaves 20–50, 0.5–1 cm wide at mid-length; inflorescence 2-pinnate with 2–10 lateral branches||Tillandsia x floridana|