~ Agavaceae
Including Dianellaceae Salisb.
Habit and leaf form. Sub shrubs, or herbs (medium to tall). Perennial; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves; rhizomatous, or tuberous. Helophytic to xerophytic. Leaves medium-sized to very large; alternate; distichous; flat, or folded; commonly leathery (or rigid); ambiguously petiolate to subsessile (by the edgewise compression at the blade/sheath junction), or sessile; sheathing. Leaf sheaths with free margins. Leaves edgewise to the stem to with `normal' orientation (the sheath and the base of the blade very strongly compressed, the leaf almost or quite unifacial around the junction); simple. Lamina entire; linear; parallel-veined; without cross-venules. Lamina margins often rough or serrulate with antrorse teeth.
Leaf anatomy. Stomata present; anomocytic.
Lamina dorsiventral. The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides (often), or solitary-prismatic (`pseudoraphides'). Vessels absent.
Stem anatomy. Secondary thickening absent. Xylem without vessels.
Root anatomy. Root xylem with vessels. Vessel end-walls scalariform and simple.
Reproductive type, pollination. Hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'; in panicles. The terminal inflorescence unit cymose. Inflorescences scapiflorous (often more or less), or not scapiflorous; terminal; sparingly to densely branched, few- to many-flowered panicles. Flowers small to medium-sized; regular to somewhat irregular; when irregular, somewhat zygomorphic. The floral asymmetry involving the perianth, or involving the perianth and involving the androecium. Flowers 3 merous; cyclic; pentacyclic. Perigone tube present (short), or absent.
Perianth of `tepals', or with distinct calyx and corolla (dubiously); 6; free, or joined; 2 whorled; isomerous; petaloid (including the outer series); similar in the two whorls, or different in the two whorls (the outer often smaller, sometimes of different texture). Calyx (if the outer whorl so designated) 3; 1 whorled; polysepalous, or gamosepalous; regular, or unequal but not bilabiate. Corolla (if the inner whorl so designated) 3; 1 whorled; polypetalous, or gamopetalous; unequal but not bilabiate, or regular; green, or white, or yellow, or orange, or blue (or violet).
Androecium 6. Androecial members free of the perianth; all equal, or markedly unequal; free of one another (usually), or coherent (rarely); when joined 1 - adelphous; 2 - whorled (3+3). Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; al\ter\ni\peri\anthial. Anthers dorsifixed, or basifixed; dehiscing via pores, or dehiscing via longitudinal slits; introrse; tetrasporangiate. The thickenings spiral. Microsporogenesis simultaneous. Anther wall of the `monocot' type. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 1 - aperturate; all seemingly (trichotomo-) sulcate.
Gynoecium 3. Carpels isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior, or partly inferior (slightly embedded, in Phormium). Ovary 3 locular. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; dry type. Placentation axile. Ovules 4-30 per locule (to `rather numerous'); arillate, or non-arillate; anatropous; bitegmic; weakly crassinucellate, or tenuinucellate (Dianella). Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating. Synergids pear-shaped (with filiform apparatus). Endosperm formation helobial.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a berry (sometimes blue), or a capsule. Capsules loculicidal, or septicidal. Seeds endospermic. Endosperm oily. Seeds winged (Phormium), or wingless. Cotyledons 1. Embryo achlorophyllous (2/2). Testa encrusted with phytomelan (even in fleshy fruits).
Physiology, biochemistry. Not cyanogenic. Proanthocyanidins present (Dianella), or absent (Phormium); when present, cyanidin. Flavonols absent. Ellagic acid absent.
Geography, cytology. Holarctic, Paleotropical, Neotropical, Australian, and Antarctic. Venezuala and Surinam and Andean. Southeast Asia, Australia, Pacific Islands, New Zealand, with Dianella extending to Africa, Madasgascar and Mascarene Is. X = 8.
Taxonomy. Subclass Monocotyledonae. Superorder Liliiflorae; Asparagales. Species about 30. Genera 5; Corynotheca, Dianella, Excremis, Phormium, Stypandra.
Illustrations. phorm844.gif
