The families of flowering plants.
IncludingTillandsieae (Tillandsiaceae) Juss.
Habit and leaf form. Herbs, or ‘arborescent’ (a few). Plants succulent (usually, more or less), or non-succulent. Perennial; with a basal aggregation of leaves (mostly acaulescent rosette plants, adapted to absorb the water which accumulates in the vase-shaped leaf rosettes — the ‘pitchers’ constituting the only habitat of of certain Utricularias, utilized by specialized frogs, etc.), or with terminal aggregations of leaves, or with neither basal nor terminal aggregations of leaves (sometimes with leaves on elongated stems), or with terminal aggregations of leaves. Self supporting, or epiphytic (commonly, even growing on cacti), or climbing (rarely, e.g. in Pitcairnia). Mesophytic, or xerophytic. Leaves alternate; spiral (mostly), or distichous (some Tillandsia species); usually leathery and fleshy, or modified into spines (usually thick and stiff, with internal water storage tissue, often spine-tipped); usually imbricate; sessile; sheathing. Leaf sheaths with free margins. Leaves simple. Lamina entire; linear, or lanceolate, or ovate, or subulate; parallel-veined; without cross-venules. Leaves exstipulate. Lamina margins entire, or serrate (often serrate-spiniferous).
General anatomy. Plants with silica bodies. Accumulated starch other than exclusively ‘pteridophyte type’.
Leaf anatomy. Epidermis containing silica bodies (one per cell, small, round, embedded in the thick inner periclinal walls). Stomata present; paracytic (or with four additional subsidiaries on the outside). Hairs present. Complex hairs present; peltate (involved in water absorption).
The mesophyll containing mucilage cells (with raphides); containing calcium oxalate crystals. The mesophyll crystals raphides. Minor leaf veins without phloem transfer cells (2 genera). Vessels present, or absent; end-walls scalariform.
Stem anatomy. Secondary thickening absent. Xylem with vessels, or without vessels. Vessel end-walls scalariform. Sieve-tube plastids P-type; type II.
Root anatomy. Root xylem with vessels; vessel end-walls scalariform, or simple (mostly scalariform).
Reproductive type, pollination. Unisexual flowersabsent. Plants hermaphrodite (usually). Floral nectaries present. Nectar secretion from the gynoecium (via septal nectaries). Pollination entomophilous, or ornithophilous (commonly by hummingbirds), or cheiropterophilous, or anemophilous (rarely — Navia).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in heads (or thyrses). The ultimate inflorescence unit seemingly racemose. Inflorescences not scapiflorous (the axes leafy to bracteate); simple or compound spikes, racemes, thyrses or heads. Flowers bracteate (the bracts distichous, often conspicuous and brightly coloured); regular, or somewhat irregular; 3 merous; cyclic; pentacyclic. Perigone tube present, or absent (the flowers epigynous to hypogynous).
Perianthwith distinct calyx and corolla; 6; free, or joined; 2 whorled; isomerous; without spots; different in the two whorls (the outer members generally much smaller, hyaline or greenish, the inner members petaloid); green, white, yellow, red, violet, and blue. Calyx 3; 1 whorled (i.e. the outer perianth whorl); polysepalous, or gamosepalous; imbricate. Corolla 3; 1 whorled; appendiculate (with coronal structures and/or paired, basal nectary scales), or not appendiculate; polypetalous, or gamopetalous (sometimes basally connate). Corolla lobes markedly longer than the tube. Corolla imbricate, or contorted; green, or white, or yellow, or orange, or red, or blue (or violet).
Androecium 6. Androecial members free of the perianth (when the perianth members are free), or adnate (when they are connate); free of one another, or coherent (sometimes with connate filaments); 2 whorled (3+3). Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; alterniperianthial. Anthers dorsifixed (peltate), or basifixed; dehiscing via longitudinal slits; introrse. Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Microsporogenesis successive. Anther wall of the ‘monocot’ type. Tapetum glandular. Pollen shed in aggregates (e.g. Cryptanthus, Hohenbergia), or shed as single grains; when aggregated, in tetrads. Pollen grains aperturate; sulcate (mostly), or foraminate (tri- or poly-, in a few Bromelioideae); 2-celled (recorded in 10 genera).
Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled.Gynoecium syncarpous; synstylovarious; superior to inferior. Ovary 3 locular. The ‘odd’ carpel anterior. Gynoecium stylate. Styles 1; apical. Stigmas 3; commissural; wet type, or dry type; papillate; Group II type and Group III type. Placentation axile. Ovules 5–50 per locule (‘several to many’); anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped. Endosperm formation helobial. Embryogeny asterad.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a capsule, or a berry. Capsules when produced, septicidal (usually), or loculicidal (rarely), or septicidal and loculicidal. Gynoecia of adjoining flowers combining to form a multiple fruit, or not forming a multiple fruit. The multiple fruits sometimes coalescing. Seeds endospermic. Endosperm peripherally oily. Seeds winged (rarely, or ‘with a pappus-like process’), or wingless. Seeds with starch. Embryo well differentiated. Cotyledons 1. Embryo achlorophyllous (Pitcairnia xanthifolia); straight (cylindrical). Testa without phytomelan.
Seedling.Hypocotyl internode present to absent. Seedling collar not conspicuous. Cotyledon hyperphyll elongated, or compact; assimilatory, or non-assimilatory; when elongated, more or less circular in t.s. (e.g. Vriesia). Coleoptile absent. Seedling cataphylls absent. First leaf dorsiventral. Primary root ephemeral (or lacking, in Tillandsioideae).
Physiology, biochemistry. Not cyanogenic. Alkaloids absent (10 species — but usually accumulating proteolytic enzymes in some parts of the plant). Proanthocyanidins absent (11 genera). Flavonols present, or absent (mostly); when present, quercetin, or kaempferol and quercetin. Ellagic acid absent. Saponins/sapogenins present (at least sometimes), or absent (?). CAM. CAM recorded directly in Abromeitiella, Acanthostachys,Aechmea, Ananas, Araeocassus, Billbergia, Bromelia,Canistrum, Cryptanthus, Deuterocohnia, Dyckia, Encholirium,Guzmania, Hechtia, Hohenbergia, Hoplophytum, Neoglaziovia,Neoregelia, Nidularium, Orthophytum, Portea, Puya,Quesnelia, Streptocalyx, Tillandsia (including non-succulents), Wittrockia. Anatomy non-C4 type (Ananas).
Geography, cytology. Sub-tropical and tropical. America and West Indies, save for one species in West Africa. X = 8–29 (often 25).
Taxonomy.Subclass Monocotyledonae. Dahlgren et al. Superorder Bromeliiflorae; Bromeliales. APG 3 core angiosperms; Superorder Lilianae; commelinid Monocot; Order Poales.
Species about 3000 (estimates having increased greatly in recent years). Genera 50–58 (with complicated synonymy); Abromeitiella, Acanthostachys, Aechmea,Alcantarea, Ananas, Androlepis, Araeococcus, Ayensua,Billbergia, Brewcaria, Brocchinia, Bromelia, Canistropsis,Canistrum, Catopsis, Chevaliera, Connellia, Cottendorfia,Cryptanthus, Deinacanthon, Deuterocohnia, Disteganthus,Dyckia, Edmundoa, Encholirium, Fascicularia, Fernseea,Fosterella, Glomeropitcairnia, Greigia, Guzmania, Hechtia,Hohenbergia, Hohenbergiopsis, Lamprococcus, Lindmania,Lymania, Macrochordion, Mezobromelia, Navia, Neoglaziovia,Neoregelia, Nidularium, Ochagavia, Ortgiesia, Orthophytum,Pepinia, Pitcairnia, Platyaechmea, Podaechmea, Portea,Pseudaechmea, Pseudananas, Puya, Quesnelia, Racinaea,Ronnbergia, Steyerbromelia, Streptocalyx, Tillandsia,Ursulaea, Vriesia, Werhauia, Wittrockia.
Economic uses, etc. In addition to pineapple (Ananas comosus), the family provides ‘vegetable hair’ used for upholstery (Tillandsia), cordage and fabric fibres (Neoglaziovia,Aechmea), and many horticultural ornamentals.