| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Biebersteiniaceae Endl.

~ Geraniaceae.

Habit and leaf form. Glandular herbs. Perennial (occasionally vegetatively stemless); with a basal aggregation of leaves, or without conspicuous aggregations of leaves; rhizomatous and tuberous. Leaves alternate; foetid; compound; pinnate, or bipinnate (or the pinnae pinnatisect); when pinnate, imparipinnate. Lamina pinnately veined; cross-venulate. Leaves stipulate. Stipules intrapetiolar (fused to the petiole).

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

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes to in spikes, or in heads, or in panicles; bi- bracteolate; regular; 5 merous; cyclic.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular; persistent; accrescent, or non-accrescent; imbricate. Corolla 5; 1 whorled; polypetalous; contorted; regular; white, or yellow, or orange; deciduous. Petals clawed, or sessile; sometimes toothed.

Androecium 10, or 15 (if the five fleshy nectariferous glands alternating with the petals are interpreted as staminodes). Androecial members free of the perianth; coherent; 1 adelphous (the filaments very shortly connate basally); 2 whorled, or 3 whorled (?). Androecium including staminodes. Staminodes 5; external to the fertile stamens; non-petaloid (i.e., represented by the whorl of glands, alternating with the petals). Stamens 10; diplostemonous; alternisepalous; both alternating with and opposite the corolla members. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 2 aperturate; colporate.

Gynoecium 5 carpelled. Carpels isomerous with the perianth. The pistil 5 celled. Gynoecium syncarpous; synovarious; superior. Ovary 5 locular (deeply lobed); sessile to stipitate. Gynoecium stylate. Styles 5; ‘styles arising from the base of the lobes and connate into a capitate stigma’. Stigmas 1; capitate. Placentation apical. Ovules 1 per locule; pendulous; anatropous to campylotropous (‘anacampylotropus’, the seed not or scarcely becoming campylotropous); bitegmic; crassinucellate.

Fruit non-fleshy; an aggregate; a schizocarp (with no persistent central column). Mericarps 5; of indehiscent, one-seeded mericarps comprising nutlets. Seeds non-endospermic. Embryo curved.

Geography, cytology. Temperate to sub-tropical. South-east Europe to central Asia. X=5.

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

Species 5. Genera 1; only genus, Biebersteinia.

General remarks. Bakker et al. (1998) inferred from rbcL and atpB sequencing that Biebersteinia merits family recognition, and that its relationships lie with Sapindales rather than Geraniales. The above description is very inadequate, e.g. re. the androecium.

Economic uses, etc. B. heterostemon is used in traditional Chinese medicine.

Illustrations. • Biebersteinia odora: Ledebour, Ic. Pl. Novarum 5 (1834). • Biebersteinia odora (from Nat. Pflanzenfam. 3 (1897). • Biebersteinia odora: Das Pflanzenreich 53 (1912).

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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