The families of flowering plants
Habit and leaf form. Shrubs, or arborescent, or herbs. Plants parasitic (on an assortment of flowering plants); haustorially parasitic; not green; parasitic on roots of the host, or on aerial parts of the host (?). When herbaceous, perennial. Leaves alternate; non-sheathing; ostensibly usually simple, or compound (overtly so in K. cystoides, perhaps basically so in the rest); unifoliolate (usually, rather than simple?), or ternate (K. cystoides). Lamina entire; cross-venulate. Leaves exstipulate. Lamina margins entire.
Leaf anatomy. The leaf lamina of leaves or leaflets dorsiventral, or bifacial, or centric. Stomata present; on both surfaces; paracytic, or anomocytic and paracytic. Hairs present; eglandular; unicellular. Unicellular hairs thick walled, simple. The mesophyll with sclerenchymatous idioblasts; containing crystals. The crystals druses.
Axial (stem, wood) anatomy. Cork cambium present; initially deep-seated. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Secondary thickening developing from a conventional cambial ring.
The vessel end-walls simple. The parenchyma scanty paratracheal. Included phloem absent.
Reproductive type, pollination. Plants hermaphrodite. Pollination entomophilous; via hymenoptera (oil-collecting bees).
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when solitary, axillary; when aggregated, in racemes; bi- bracteolate (the bracteoles leafy); minute; very irregular; zygomorphic. The floral irregularity involving the perianth and involving the androecium. Flowers cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; (8–)10; 2 whorled; isomerous to anisomerous; all petaloid (including the calyx). Calyx (4–)5; 1 whorled; polysepalous; petaloid, unequal but not bilabiate (commonly with the three outer members larger than the two inner and often nearly enclosing the rest of the flower, rarely all the members reflexed); imbricate; with the median member anterior. Corolla (4–)5; 1 whorled; polypetalous, or partially gamopetalous (the three upper members sometimes connate via their claws); imbricate; unequal but not bilabiate (the two lower, abaxial members smaller, very different, commonly broad and thick, and often modified into lipid-secreting glands). Petals clawed (the three adaxial members), or sessile (the abaxial members).
Androecium (3–)4(–5). Androecial members adnate (sometimes adnate to the claws of the upper petals), or free of the perianth; markedly unequal (declinate); free of one another, or coherent; when joined, 1 adelphous (the filaments basally connate); 1 whorled. Androecium exclusively of fertile stamens, or including staminodes (rarely). Staminodes when present, 1 (in the form of a fifth, sterile, anterior stamen); in the same series as the fertile stamens; representing the anterior median member. Fertile stamens representing the posterior-lateral pair and the anterior-lateral pair. Stamens (3–)4 (posterior); reduced in number relative to the adjacent perianth; oppositisepalous (alternating with the upper petals); alternating with the corolla members; filantherous (the filaments thick). Anthers apically dehiscing via pores, or dehiscing via short slits; tetrasporangiate. Pollen grains aperturate; 3(–4) aperturate; colporate (to ruporate).
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled, or 2 celled. Gynoecium syncarpous (but pseudomonomerous); disguisedly eu-syncarpous (one carpel developing, the other vestigial); superior. Ovary 1(–2) locular. Gynoecium stylate. Styles 1; obliquely apical. Stigmas 1 (discoid or punctiform). Placentation apical. Ovules in the single cavity 2; pendulous; collateral; anatropous; bitegmic.
Fruit non-fleshy (dry); indehiscent; achene-like (usually covered with bristles or spines, these often retrorsely barbed); 1 seeded. Seeds non-endospermic. Embryo well differentiated. Cotyledons 2 (thick). Embryo straight.
Physiology, phytochemistry. Iridoids not detected (S.R. Jensen, unpublished). Saponins/sapogenins absent. Aluminium accumulation not found.
Geography, cytology. Holarctic and Neotropical. Temperate to tropical. Warm Central America. X = 6.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rutiflorae (probably misplaced); Polygalales. Cronquists Subclass Rosidae; Polygalales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Zygophyllales.
Species 25. Genera 1; only genus, Krameria.
General remarks. Linked with Zygophyllaceae s. str. on rbcL sequence data by Chase et al. (1993) and Sheahan and Chase (1996).
Illustrations. • Krameria grayi, K. glandulosa and K. imparata: Adams (1944), Ill. Fl. Pacific States. • Krameria lappaceae (as triandra): Nat. Pflanzenfam. III (1894). • Le Maout and Decaisne: Krameria. • Krameria cistoidea: 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: 5th March 2018. delta-intkey.com/angio’.