The families of flowering plants
Including Dactylanthaceae (Engler) Takhtajan, Hachettiaceae Van Tiegh., Helosidaceae (Heloseaceae) (Schott & Endlicher) Van Tiegh., Langsdorffiaceae Van Tiegh., Lophophytaceae Horan., Mystropetalaceae Takhtajan, Latraeophilaceae Leandro ex A. St.-Hil., Sarcophytaceae Horan.; excluding Cynomoriaceae.
Habit and leaf form. Bizarre, fleshy herbs. Plants of very peculiar vegetative form; fungoid (the above-ground parts constitute the inflorescence, which is remarkably fungoid in appearance: pallid, brown, pink or purplish, bearing numerous flowers that are among the smallest known. The underground parts, which are attached to the host root, may be the size of a pineapple and are tuber-like in appearance, exhibiting scale-leaves in only one genus. The inflorescence develops within the tuber, ultimately rupturing it and exhibiting its remains as a volva at the base). Leaves much reduced (then subterranean only), or absent. Plants rootless (at least in the normal sense); more or less succulent; totally parasitic. Parasitic on roots of the host (of trees). Annual to perennial (without chlorophyll). Leaves when present, membranous.
Axial (stem, wood) anatomy. Primary vascular tissues of rhizomes and peduncles comprising a ring of bundles, or comprising two or more rings of bundles, or consisting of scattered bundles; collateral. Internal phloem absent. Secondary thickening absent. The axial xylem with vessels, or without vessels.
The vessel end-walls simple.
Reproductive type, pollination. Plants monoecious, or dioecious.
Inflorescence, floral, fruit and seed morphology. Inflorescences with densely crowded flowers. Flowers minute.
Perianth sepaline (sometimes, in male flowers), or vestigial to absent; when present, 3–8 (lobed); when present, free, or joined.
Androecium 1–2 (in achlamydeous male flowers), or 3–8 (equalling and opposite P). Androecial members free of one another, or coherent. Androecium exclusively of fertile stamens. Stamens 1–8; often isomerous with the perianth. Anthers cohering, or separate from one another; dehiscing via pores, or dehiscing via short slits; bilocular to four locular to many locular; tetrasporangiate. Anther epidermis persistent. Anther wall with no differentiation of an endothecium; of the dicot type. Tapetum probably glandular. Pollen grains aperturate, or nonaperturate; when aperturate, (2–)3–5 aperturate, or 3–4(–5) aperturate; colpate, or porate, or foraminate; 2-celled.
Gynoecium 1–2(–3) carpelled. The pistil 1–2(–3) celled. Gynoecium syncarpous; synovarious; superior to inferior. Ovary 1–2(–3) locular. Gynoecium stylate (usually), or non-stylate. Styles apical. Stigmas 1, or 2. Placentation apical. Ovules 1 per locule; pendulous; without integuments. Embryo-sac development Polygonum-type, or Allium-type. Antipodal cells formed, or not formed; when formed, 1, or 2; not proliferating. Endosperm formation cellular. Endosperm haustoria present. Embryogeny piperad.
Fruit non-fleshy; indehiscent; a drupe, or a nut. The drupes with one stone. Fruit 1 seeded. Seeds endospermic; without a testa. Embryo rudimentary at the time of seed release.
Seedling. Germination type inapplicable cotyledons lacking.
Physiology, phytochemistry. Not cyanogenic. Alkaloids absent (one species).
Geography, cytology. All but one sub-tropical to tropical. Pantropical.
Taxonomy. Subclass Dicotyledonae; Crassinucelli, or Tenuinucelli (?). Dahlgrens Superorder Balanophoriflorae; Balanophorales. Cronquists Subclass Rosidae; Santalales. APG 3 core angiosperms; core eudicot; Superorder Santalanae; Order Santalales.
Species 120. Genera 17; Balanophora, Chlamydophytum, Corynaea, Dactylanthus, Ditepalanthus, Exorhopala, Hachettea, Helosis, Langsforffia, Lophophytum, Mystropetalon, Ombrophytum, Rhopalocnemis, Sarcophyte, Scybalium, Thonningia.
Illustrations. • Habit and technical details: Scybalium (Lindley).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2016. delta-intkey.com’.