| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Pteridophyllaceae (Murb.) Sugiura ex Nak.

~ Fumariaceae, Papaveraceae sensu lato

Habit and leaf form. Stemless herbs (with Blechnum-like leaves); seemingly non-laticiferous, without coloured juice (cf. Hypecoum?). Perennial; with a basal aggregation of leaves (the leaves all radical); rhizomatous. Leaves alternate (surrounded at the base by several large, orbicular, membranous cataphylls); simple, or compound; if considered ‘compound’, very evenly pinnate. Lamina if considered ‘entire’, very deeply dissected; regularly, evenly pinnatifid. Leaves exstipulate.

General anatomy. Plants seemingly without laticifers (?).

Leaf anatomy. Stomata present; mainly confined to one surface (the abaxial); anomocytic. The mesophyll without sclerenchymatous idioblasts.

Axial (stem, wood) anatomy. Primary vascular tissues probably comprising a ring of bundles (?). Secondary thickening absent.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in fascicles. Inflorescences scapiflorous (the scapes erect, simple or very slightly branched, bearing more or less distant, two-flowered fascicles of flowers on slender pedicels). Flowers regular to somewhat irregular (almost regular); cyclic. Free hypanthium absent.

Perianth with distinct calyx and corolla; 6; 3 whorled (2+2+2); isomerous. Calyx 2; 1 whorled; polysepalous; neither appendaged nor spurred (and the sepals not lobed); not persistent (caducous); open in bud (not enclosing the flower bud). Corolla 4; 2 whorled (2+2); polypetalous; unequal but not bilabiate, or regular (the petals ‘subequal’); white; deciduous (caducous). Petals entire.

Androecium ostensibly 4. Androecial members unbranched; free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4; oppositisepalous; alternating with the corolla members (diagonal); very shortly filantherous (without basal nectaries). Anthers oblong; all bilocular; tetrasporangiate (?). Pollen shed as single grains. Pollen grains aperturate; (2–)3(–4) aperturate; colpate.

Gynoecium 2 carpelled. Carpels isomerous with the perianth. The pistil 1 celled. Gynoecium syncarpous; synstylovarious; superior. Ovary 1 locular (flattened). Gynoecium stylate. Styles 1; apical. Stigmas 2; commissural. Placentation basal. Ovules in the single cavity 2–4; non-arillate (at least, the seeds neither strophiolate nor carunculate); anatropous, or anatropous to campylotropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Endosperm formation nuclear.

Fruit non-fleshy; dehiscent; capsular-indehiscent. Capsules (bi-) valvular (siliculiform, dehiscence acropetal). Fruit many-seeded.

Physiology, phytochemistry. Alkaloids present.

Geography, cytology. Holarctic. Temperate. Japan. N = 9.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Ranunculiflorae; Papaverales (?). Cronquist’s Subclass Magnoliidae; Papaverales. APG III core angiosperms; peripheral eudicot; Superorder Ranunculanae. APG IV Order Ranunculales (as a synonym of Papaveraceae).

Species 1 (Pteridophyllum racemosum). Genera 1; only genus, Pteridophyllum.

General remarks. Differing from Papaveraceae (q.v.) in habit and inflorecence, as well as in androecium, gynoecium and ovule, fruit and seed morphology. No reliable anatomical data located.

Illustrations. • Pteridophyllum racemosum: Bot. Mag. 144 (1918). • Pteridophyllum racemosum (Chittenden).

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: 8th June 2026. delta-intkey.com’.

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