Agavaceae

Abstract

Plants small to gigantic, perennial, monocarpic or polycarpic, acaulescent or arborescent, sometimes caespitose. Roots fibrous or fleshy; rhizomes spreading or thick and upright. Leaves rosulate, spiral, annual or long-lived, linear, lanceolate, elliptic or ovate, fibrous, rigid or flexible, the texture thin, thickened and hard, or succulent, pale to dark green, often glaucous, maculate in some species; the apex with a short or long soft or pungent point; margins entire, denticulate to coarsely toothed or filiferous. Flowering stems terminal or axillary, sometimes huge, bracteate. Inflorescence a panicle, raceme, or spike. Flowers perfect, often protandrous, hypogynous, or epigynous, actinomorphic to zygomorphic, never provided with a pericladium or articulate with the pedicel. Tepals 6, petaline, semisucculent, waxy, green, greenish yellow or white, sometimes tinged with maroon, or red to coral, free or united into a long or short tube, the lobes erect, spreading or revolute. Stamens 6, with long or short filaments, included or long exserted; filaments thin or variously thickened, smooth, papillate or short-hairy, the long ones bent in bud; anthers bithecate, dorsifixed, versatile, linear, oblong, or sagittate, introrsely dehiscent with longitudinal slits. Gynoecium of 3 united carpels, ovary superior or inferior, trilocular, ovoid to cylindrical, fleshy, with septal nectaries; ovules numerous, in 2 axile rows in each locule, anatropous; style single or styluli free (Yucca), long or short, included or exserted, thickened in Furcraea, Beschorneria, and Yucca; stigma single and capitate or 3-lobed or (Yucca) stigmas 3 on separate branches. Fruit a loculicidally dehiscent, erect capsule, or (Yucceae) sometimes septicidally dehiscent, or indehiscent and dry or fleshy. Seeds mostly flat, sometimes bordered with a narrow wing, cuneate, black. Embryo cylindrical, straight or slightly curved, oriented along the long axis of the seed.