Giant, tufted, rosulate perennials, the older plants forming dense clumps with a short vertical subterranean stem. Leaves bifacial, basal, spirally arranged, linear to narrow-lanceolate, with massive starch-filled bases forming a bulb; margin of sheath thin, filmy, completely encircling the axis; leaf tip a cylindrical, obtuse, brown prolongation the surface of which is ultimately shed leaving a tuft of threadlike fibres. Inflorescence a sparse or densely contracted thyrse attaining a height of 5.5 m and terminating an axis which towards its base bears abundant leaves similar to, but much smaller than, those of the rosette. Large, often bright red bracts subtending the inflorescence branches and flowers. Flowers large, epigynous, with short pedicels each of which bears a prophyll. Tepals 6, petaloid, 5-nerved, nearly equal and up to 18 cm in length, fused at the base to form a nectar cup; the free portions spreading, eventually caducous; inner 3 tepals slightly dilated at base. Stamens 3 + 3, epitepalous, with linear or basally dilated erect filaments extending beyond the tepals; anthers to 3 cm long, tetrasporangiate, peltate with the apex of the filament enclosed in a tube formed by the connective, extrorse, bilocular, dehishing longitudinally by slits. Gynoecium syncarpous, 3-carpellate, 3-locular; septal nectaries well developed, opening around the base of the style; style simple, slender, with an obtuse, triangular stigma; ovules numerous, borne on axile placentas in 2 rows per locule. Fruit a loculicidal capsule. Seeds numerous and variable in size but usually provided with a lateral wing. Testa yellow to red-brown due to the presence of the breakdown products of phlobaphene (Huber 1969); endosperm composed of thin-walled cells rich in fats and aleurone. Embryo straight, with a broad obtriangular cotyledon.
Unable to display preview. Download preview PDF.
- Blunden, G., Yi Yi, Devers, K. 1973. The comparative leaf anatomy of Agave, Beschorneria, Doryanthes, and Furcraea species (Agavaceae: Agaveae). Bot. J. Linn. Soc. 66: 157–179, 9 figures.Google Scholar
- Cave, M.S. 1955. Sporogenesis and the female gametophyte of Phormium tenax. Phytomorphology 5: 247–253.Google Scholar
- Chase, M.W. et al. 1995. See general references.Google Scholar
- Dahlgren, R.M.T. et al. 1985. See general references.Google Scholar
- Goebel, K. 1905. Organography of plants. Pt II. Engl. Transi. ( I. B. Balfour). Oxford: Clarendon Press.Google Scholar
- Haberlandt, G. 1914. Physiological plant anatomy. Engl. Transl. (Drummond). London: Macmillan.Google Scholar
- Hegnauer, R. 1963, 1972. See general references.Google Scholar
- Huber, H. 1969. See general references.Google Scholar
- Newman, I.V. 1928. The life history of Doryanthes excelsa. Part 1. Some ecological and vegetative features and spore production. Proc. Linn. Soc. N.S.W. 53: 499–558, pl. 32–35.Google Scholar
- Newman, I.V. 1929. The life history of Doryanthes excelsa. Part II. The gametophytes, seed production, chromosome number and general conclusion. Proc. Linn Soc. N.S.W. 54: 411–435, pl. 17–29.Google Scholar
- Satô, D. 1938. Karyotype alteration and phylogeny IV. Karyotypes in Amaryllidaceae with special reference to SAT-chromosomes. Cytologia 9: 203–242.Google Scholar
- Takhtajan, A.L. 1982. See general references.Google Scholar
- Troll, W. 1939. Vergleichende Morphologie der höheren Pflanzen 1 Band, 2. Teil. Berlin: Borntraeger.Google Scholar