| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Crypteroniaceae A. DC.

~ Penaeaceae

Including Henslowiaceae Lindl. corr. Endl.; excluding Alzateaceae, Rhynchocalycaceae.

Habit and leaf form. Trees, or shrubs. Helophytic, or mesophytic. Leaves opposite; leathery; petiolate; simple. Lamina entire; pinnately veined (with a continuous submarginal vein); cross-venulate (brochidodromous). Leaves stipulate to exstipulate (the stipules rudimentary, lateral). Lamina margins entire.

Leaf anatomy. Stomata present; anomocytic (Dactylocladus), or paracytic. Adaxial hypodermis present. The mesophyll with sclerenchymatous idioblasts (unbranched), or without sclerenchymatous idioblasts (Axinandra); containing crystals. The crystals druses.

Axial (stem, wood) anatomy. Young stems tetragonal in section, or flattened. Cork cambium present; initially deep-seated, or initially superficial (Dactylocladus). Nodes unilacunar. Primary vascular tissues in a cylinder, without separate bundles; bicollateral. Internal phloem present. Secondary thickening developing from a conventional cambial ring, or anomalous (?). Primary medullary rays narrow. The axial xylem with vessels.

The wood diffuse porous. The vessels medium; solitary, radially paired, and in radial multiples. The vessel end-walls simple. The vessels with vestured pits. The axial xylem with fibre tracheids; without septate fibres. The parenchyma paratracheal. ‘Included’ phloem absent. The wood not storied.

Reproductive type, pollination. Unisexual flowers present, or absent. Plants hermaphrodite, or polygamodioecious.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in panicles. Inflorescences axillary; racemes, spikes or panicles of subsessile flowers. Flowers numerous, very small; regular; 4–5(–6) merous. Free hypanthium present (this cupular or shortly tubular). Hypogynous disk absent.

Perianth with distinct calyx and corolla, or sepaline (the corolla absent in Crypteronia); (8–)10, or 4–5(–6) (Crypteronia); 1 whorled, or 2 whorled; isomerous. Calyx 4–5(–6); 1 whorled; polysepalous (on the hypanthium?), or gamosepalous (? — the lobes (or sepals) thin, membranous); 4–5(–6) blunt-lobed; persistent, or not persistent (Axinandra); valvate. Corolla when present, (4–)5; 1 whorled; polypetalous, or gamopetalous (Axinandra); deciduous (as a coneshaped unit in Axinandra, the individual petals falling in the other genera).

Androecium 4–5(–6), or 10 (Axinandra). Androecial members free of the perianth, or adnate (epipetalous and episepalous in Axinandra); free of one another; 1 whorled, or 2 whorled (Axinandra). Androecium exclusively of fertile stamens. Stamens 4–5(–6), or 10; isomerous with the perianth, or diplostemonous; alternisepalous, or oppositisepalous (?); filantherous (the filaments long or short). Anthers small; tetrasporangiate (the sporangia lateral to terminal). Anther wall of the ‘dicot’ type (in Axinandra). Pollen shed as single grains. Pollen grains aperturate; 4–6 aperturate; colpate and colporate (bisyncolporate with two indistinct subsidiary colpi (Crypteronia), or tricolporate with three distinct subsidiary colpi); 2-celled.

Gynoecium 2(–4) carpelled (Crypteronia), or (3–)4–5 carpelled (Dactylocladus), or (2–)3 carpelled (Axinandra). Carpels reduced in number relative to the perianth to isomerous with the perianth. The pistil 1(–5) celled. Gynoecium syncarpous; eu-syncarpous; superior to inferior. Ovary unilocular; 1 locular (but the septa sometimes joined basally). Epigynous disk absent. Gynoecium stylate. Styles 1; attenuate from the ovary; apical; much longer than the ovary (persistent complete with the stigma, or (Axinandra) non-persistent). Stigmas 1; capitate (or punctate). Placentation basal, or basal to parietal. Ovules in the single cavity 6–15; horizontal, or ascending; anatropous. Outer integument contributing to the micropyle (in Axinandra). Embryo-sac development Polygonum-type (Axinandra).

Fruit non-fleshy; dehiscent; a capsule (indurated). Capsules loculicidal and valvular (2–5 valved, the valves usually remaining connected at the style). Fruit 50–100 seeded (‘many’). Seeds non-endospermic; small; winged (at the micropylar or chalazal end), or wingless. Cotyledons 2. Embryo central or basal. Micropyle not zigzag.

Physiology, phytochemistry. Aluminium accumulation demonstrated.

Geography, cytology. Paleotropical. Tropical. Tropical Asia.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Myrtales.

Species 10. Genera 3; Crypteronia, Axinandra, Dactylocladus.

Illustrations. • Crypteronia paniculata: Kooders and Valeton, Atlas der Baumgarten Java(1814). • Crypteronia paniculata (Hutchinson). • Dactylocladus stenostachys: Hook. Ic. Pl. 24 (1895).

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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