The families of flowering plants

L. Watson and M.J. Dallwitz

Pennantiaceae J.G. Agardh

~ Icacinaceae.

Habit and leaf form. Rainforest trees (to 30 m high, with buttressed, leaning trunk and characteristically zig-zagging branchlets (Australian P. cunninghamii), or shrubs, or lianas (rarely). Self supporting, or climbing. Leaves alternate; not gland-dotted; without marked odour; simple. Lamina entire; pinnately veined. Leaves exstipulate. Lamina margins entire, or dentate (or lobed). Leaf development not ‘graminaceous’.

Leaf anatomy. Stomata paracytic. Hairs present. Multicellular hairs uniseriate.

Axial (stem, wood) anatomy. Nodes tri-lacunar. Secondary thickening developing from a conventional cambial ring. Primary medullary rays wide.

The vessel end-walls commonly reticulately perforated, or scalariform (with thin and numerous bars).

Reproductive type, pollination. Plants hermaphrodite, or dioecious, or polygamomonoecious. Female flowers with staminodes, or without staminodes. Gynoecium of male flowers pistillodial, or vestigial, or absent.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes, or in panicles. The ultimate inflorescence units cymose. Flowers regular; mostly 5 merous; tetracyclic. Free hypanthium absent.

Perianth with distinct calyx and corolla, or petaline (the calyx very small, rudimentary in P. cunninghamii); 5, or 10; 1 whorled, or 2 whorled; isomerous. Calyx if detectable, 5; 1 whorled; gamosepalous (into a tube); tubular; regular; persistent. Corolla 5; polypetalous, or gamopetalous; valvate; regular; white.

Androecium 5. Androecial members free of the perianth, or adnate (to the corolla tube); free of one another; 1 whorled. Stamens 5; isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous. Anthers dorsifixed; latrorse, or introrse.

The pistil usually, 1 celled. Gynoecium syncarpous; synovarious, or synstylovarious, or eu-syncarpous (?); superior. Ovary 1 locular, or 2 locular. Gynoecium non-stylate, or stylate. Styles when present, 1, or 2. Ovules in the single cavity 2; when more than one-locular, 2 per locule; pendulous; arillate.

Fruit fleshy, or non-fleshy; indehiscent; a drupe. The drupes with one stone.

Physiology, phytochemistry. Cyanogenic.

Geography, cytology. Australian and Antarctic. Temperate to tropical. Australia (E. Australia, Norfolk Island, New Zealand.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Corniflorae; Cornales. Cronquist’s Subclass Rosidae; Celastrales. APG III core angiosperms; core eudicot; Superorder Asteranae; campanulid. APG IV Order Apiales.

Species 4. Genera 1; Pennantia.

General remarks. This inadequate description lacks information on informative ‘esoteric characters’, expecially anther development and embryology. As it stands, it offers no support for recent removal of this genus from Icacinaceae (Cornales or Celastrales), and does not effectively distinguish it from the present descriptions of either Icacinaceae or Celastraceae.

Economic uses, etc. Including cultivated ornamentals.

Illustrations. • Pennantia corymbosa: Hooker, Fl. Novae-Zelandiae (1853). • Pennantia cunninghamii: habit. • Pennantia cunninghamii: leaves and inflorescence.

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: 15th April 2018.’.