DELTA home

The families of flowering plants

L. Watson and M.J. Dallwitz

Grubbiaceae Endl.

Including Ophiraceae Reichb., Ophiriaceae Arn.

Habit and leaf form. Ericoid shrubs. Xerophytic. Leaves opposite (decussate); rolled; leathery; simple. Lamina entire; linear, or lanceolate. Leaves exstipulate (but the opposite bases connected on either side by transverse ridges). Lamina margins strongly revolute.

Leaf anatomy. The leaf lamina dorsiventral. Stomata present; mainly confined to one surface (abaxial); anomocytic. Hairs present; exclusively eglandular; unicellular. Unicellular hairs simple (sometimes with verrucose thickenings). Complex hairs absent.

Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar. Secondary thickening developing from a conventional cambial ring.

The vessel end-walls oblique; scalariform. The axial xylem with tracheids; with fibre tracheids. The parenchyma scanty, diffuse.

Root anatomy. Lateral roots without a conspicuous endodermis.

Reproductive type, pollination. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The fruiting inflorescences conelike. The ultimate inflorescence units cymose. Inflorescences axillary; small, axillary, often villous 3-flowered dichasia, or many-flowered compound dichasia. Flowers bracteate; sessile, minute; regular; cyclic. Free hypanthium absent.

Perianth sepaline (apetalous according to Cronquist, 1981); ostensibly 4 (cf. Cronquist, but interpreted by Fagerlind (1947) as 2 bracteiform plus 2 vestigial calyx members, and a corolla comprising 2+2 diagonally disposed and valvate); 1 whorled, or 4 whorled (depending on interpretation). Calyx 4 (by either interpretation, as applied to the calyx of Cronquist or the corolla of Fagerlind); 1 whorled (Cronquist), or 2 whorled (under Fagerlind’s interpretation); small, polysepalous; valvate.

Androecium 8. Androecial members free of the perianth and adnate (the antesepalous members slightly adnate to the base of the sepals); markedly unequal (the antesepalous members somewhat longer); free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous; alternisepalous (if the ostensible calyx is actually corolla, cf. Fagerlind), or oppositisepalous; filantherous (liguliform, laterally compressed). Anthers adnate (to the distal part of the filament); becoming inverted during development, their morphological bases ostensibly apical in the mature stamens; dehiscing via longitudinal slits; ostensibly extrorse (as a result of ontogenetic inversion). Pollen shed as single grains. Pollen grains aperturate; 3 aperturate; colporate.

Gynoecium 2 carpelled. Carpels isomerous with the perianth. The pistil 1 celled, or 2 celled. Gynoecium syncarpous; eu-syncarpous; inferior. Ovary at least initially, 2 locular (but with an ephemeral partition, and subsequently becoming unilocular). Epigynous disk present (annular, hairy). Gynoecium stylate. Styles 1; apical. Stigmas 1; 1 lobed, or 2 lobed. Placentation apical. Ovules 1 per locule; pendulous; anatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Endosperm formation cellular. Endosperm haustoria present; chalazal and micropylar.

Fruit non-fleshy; dehiscent; achene-like, or a drupe. Gynoecia of adjoining flowers combining to form a multiple fruit (the compact cluster representing each inflorescence resembling a cupressaceous cone). The multiple fruits more or less coalescing. Dispersal unit the inflorescence. Fruit (the true fruit) 1 seeded. Seeds endospermic. Endosperm oily. Cotyledons 2. Embryo straight (long, cylindrical).

Physiology, phytochemistry. Iridoids not detected.

Geography, cytology. Cape. Temperate to sub-tropical. South Africa.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli (?). Dahlgren’s Superorder Rosiflorae; Cunoniales (?). Cronquist’s Subclass Dilleniidae; Ericales. APG III core angiosperms; core eudicot; Superorder Asteranae. APG IV Order Cornales.

Species 5. Genera 2; only genera, Grubbia, Strobilocarpus.

General remarks. See Fagerlind (1947). Sv. Bot. Tidskr. 41, 315–320.

Illustrations. • Grubbia rosmarinifolia (Hutchinson). • Grubbia rosmarinifolia: Faguet, Adansonia 3 (1863).

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.’.