The Families of Flowering Plants

L. Watson and M. J. Dallwitz

Tiliaceae Juss.

Including Sparmanniaceae J.G. Agardh

Excluding Elaeocarpaceae, Muntingiaceae, Oceanopapaveraceae

Habit and leaf form. Trees and shrubs, or herbs (rarely); non-laticiferous and without coloured juice; leptocaul. Mesophytic. Leaves alternate; spiral, or distichous (often, or at least two ranked on the upper half of the shoot); petiolate; non-sheathing; simple. Lamina dissected, or entire; conspicuously asymmetric (commonly), or not conspicuously asymmetric; when dissected, palmatifid; usually palmately veined. Leaves stipulate. Stipules intrapetiolar; free of one another; caducous (often), or persistent. Leaves without a persistent basal meristem. Domatia recorded (9 genera); represented by hair tufts (nearly always), or pockets (rarely).

Leaf anatomy. Mucilaginous epidermis present, or absent. Stomata present; usually anomocytic. Hairs present, or absent; eglandular, or glandular; unicellular, or multicellular. Complex hairs present, or absent; peltate, or stellate, or capitate.

Lamina dorsiventral (usually), or isobilateral (sometimes ‘consisting wholly of palisade’); with secretory cavities, or without secretory cavities. Secretory cavities containing mucilage; Secretory cavities schizogenous, or lysigenous. The mesophyll containing mucilage cells. Minor leaf veins without phloem transfer cells (Entelea, Sparmannia).

Stem anatomy. Secretory cavities present (usually, in pith and cortex); with mucilage. Cork cambium present; initially superficial. Nodes tri-lacunar. Primary vascular tissue in a cylinder, without separate bundles; centrifugal. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones. ‘Included’ phloem absent. Xylem with tracheids, or without tracheids; with fibre tracheids (with small bordered pits in Tilia), or without fibre tracheids; with libriform fibres; with vessels. Vessel end-walls simple. Vessels without vestured pits. Tile cells present (Durio and Pterospermum types). Wood storied, or partially storied (VPI); parenchyma apotracheal, or paratracheal. Sieve-tube plastids S-type.

Reproductive type, pollination. Plants hermaphrodite, or monoecious, or polygamomonoecious.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’ (and sometimes paired); axillary; in cymes. The terminal inflorescence unit cymose (mostly), or racemose. Inflorescences axillary (or displaced-axillary, with the foliage leaf subtending both a vegetative and an inflorescence bud: see Rendle (1930) for interpretation); mostly cymes, often very complex. Flowers regular; (3–)5 merous; cyclic, or partially acyclic. Sometimes the androecium acyclic. Floral receptacle developing an androphore, or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla, or sepaline (corolla rarely lacking); (4–)5–10; 2 whorled (usually), or 1 whorled; isomerous (usually). Calyx (3–)5; 1 whorled; polysepalous, or gamosepalous (sometimes basally connate); regular; imbricate. Epicalyx present, or absent. Corolla normally (4–)5; 1 whorled; polypetalous; imbricate, or contorted; regular. Petals deeply bifid, or entire.

Androecium (10–)15–100 (usually ‘many’). Androecial members branched; maturing centrifugally; free of the perianth (inserted at the base of the petals, or on an androphore); free of one another, or coherent; when coherent 1 adelphous, or 5 adelphous, or 10 adelphous; 1–10 whorled (or acyclic and covering an androphore). Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 5–15 (?); non-petaloid. Stamens (10–)15–100 (usually ‘many’); diplostemonous (rarely), or triplostemonous to polystemonous. Anthers dehiscing via pores, or dehiscing via short slits, or dehiscing via longitudinal slits; bilocular (by contrast with Malvaceae); bisporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with one middle layer, or initially with more than one middle layer (1 or 2); of the ‘basic’ type. Tapetum glandular. Pollen grains aperturate; (2–)3–4 aperturate, or 6 aperturate; porate (3–4), or colporate (most commonly tricolporate), or foraminate (oligo-), or rugate (6-); 2-celled.

Gynoecium 2–100 carpelled (to ‘many’). Carpels isomerous with the perianth, or reduced in number relative to the perianth, or increased in number relative to the perianth. The pistil 1 celled, or 2–100 celled (to ‘many’). Gynoecium syncarpous; eu-syncarpous; superior, or inferior (Neotessmannia). Ovary 1 locular (the septa incomplete), or 2–100 locular (to ‘many’); sessile. Gynoecium stylate. Styles 1; apical. Stigmas 1; capitate (or lobed); dry type; papillate; Group II type. Placentation when unilocular (i.e. rarely), free central; usually axile. Ovules in the single cavity when unilocular, 2–100 (to ‘many’); (1–)2–50 per locule (to ‘many’); ascending (usually, or always with Neotessmannia excluded?); more or less apotropous (?); with ventral raphe, or with lateral raphe; arillate (sometimes), or non-arillate; hemianatropous to anatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle, or not contributing to the micropyle. Endothelium differentiated. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked (or very elongated). Endosperm formation nuclear. Embryogeny onagrad, or asterad.

Fruit fleshy, or non-fleshy; dehiscent, or indehiscent, or a schizocarp. Mericarps when schizocarpic, 2–100 (to ‘many’); comprising nutlets, or samaroid, or comprising drupelets (or other?). Fruit when non-schizocarpic, a capsule (usually), or capsular-indehiscent, or a drupe, or a nut (or other?). Capsules denticidal, or poricidal, or loculicidal (or other?). Seeds endospermic. Endosperm oily. Cotyledons 2; flat. Embryo chlorophyllous (4/8); curved, or bent. Micropyle zigzag.

Seedling. Germination phanerocotylar.

Physiology, biochemistry. Not cyanogenic. Alkaloids present (rarely), or absent. Iridoids not detected. Proanthocyanidins present; cyanidin. Flavonols present, or absent; kaempferol, or kaempferol and quercetin. Ellagic acid absent (4 species, 4 genera). Arbutin absent. Aluminium accumulation not found. Sugars transported as oligosaccharides + sucrose (predominantly, but some myoinositol usually detected as well). C₃. C₃ physiology recorded directly in Corchorus, Tilia.

Geography, cytology. Temperate to tropical. Cosmopolitan, except for frigid regions. X = 7–41.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Malvales. Cronquist’s Subclass Dilleniidae; Malvales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Malvales. Species 450. Genera about 50; Ancistrocarpus, Apeiba, Asterophorum, Berrya, Brownlowia, Burretiodendron, Christiana, Clappertonia, Colona, Corchorus, Craigia, Desplatsia, Diplodiscus, Duboscia, Eleutherostylis, Entelea, Erinocarpus, Glyphaea, Goethalsia, Grewia, Hainania, Heliocarpus, Hydrogaster, Jarandersonia, Luehea, Lueheopsis, Microcos, Mollia, Mortoniodendron, Neotessmannia, Pentace, Pentaplaris, Pseudocorchorus, Schoutenia, Sicrea, Sparmannia, Tahitia, Tetralix, Tilia, Trichospermum, Triumfetta, Vasivaea, Vinticena.

Bayer et al. expand Malvaceae to include Bombacaceae, Sterculiaceae and Tiliaceae, consequent on a combined analysis of plastid atpB and rbcL DNA sequences.

Economic uses, etc. Tilia supplies lumber (basswood, whitewood), also ornamental and shade trees popular for street plantings.

Illustrations. • Technical details (Tilia). • Technical details (Apeiba, Berrya, Triumfetta).

Quotations

In the line-grove which weather-fends your cell
(‘Tempest’, v., 1. ‘Line’ deriving from ‘linden’, subsequently corrupted to ‘lime’ — re. Tilia)