| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Quillajaceae D. Don

~ Rosaceae-Quillajeae in older treatments.

Habit and leaf form. Trees. To 15–20 m high. Leptocaul. Leaves persistent; small to medium-sized (3–5 cm long); alternate; spiral; leathery; petiolate; non-sheathing; not gland-dotted; simple. Lamina entire; oblong to ovate (?); pinnately veined. Leaves stipulate. Stipules intrapetiolar; free of one another; small, scaly; caducous. Lamina margins entire, or serrate. Leaf development not ‘graminaceous’.

Leaf anatomy. The mesophyll containing crystals. The crystals solitary-prismatic (with true styloids recorded).

Axial (stem, wood) anatomy. The vessel end-walls scalariform.

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite, or polygamomonoecious (within the inflorescence, the laterals male, the centrals female-fertile). Floral nectaries present. Nectar secretion from the disk.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in corymbs (these dense). The ultimate inflorescence units cymose. Inflorescences terminal and axillary; dense corymbs, 3–5 flowered. Flowers bracteate; bi- bracteolate; small (to 15 mm in diameter); regular; basically 5 merous (with a few exceptional flowers); pentacyclic.

Perianth with distinct calyx and corolla; 10(–14). Calyx 5(–7); 1 whorled; briefly gamosepalous; blunt-lobed (the lobes broadly ovate). Calyx lobes markedly longer than the tube. Calyx regular; valvate; with the median member anterior. Corolla 5(–7); 1 whorled; polypetalous; contorted; regular; white; plain. Petals small, sessile.

Androecium 10. Androecial members maturing centripetally; free of the perianth; free of one another; 2 whorled. Stamens 10; diplostemonous; oppositisepalous; both alternating with and opposite the corolla members (5 inserted at the base of the disk, 5 alternating with them and inserted at the apices of the disk lobes); filantherous. Anthers dorsifixed; dehiscing via longitudinal slits; tetrasporangiate. The initial microspore tetrads tetrahedral. Tapetum glandular.

Gynoecium 5(–7) carpelled (the carpels antesepalous, sessile, tomentose). Carpels reduced in number relative to the perianth. The pistil 5 celled. Gynoecium syncarpous; semicarpous (the carpels proximally fused); superior. Carpel 10–50 ovuled (many). Placentation marginal (the ovules flattened). Ovary 5(–7) locular. Stigmas distal, along the revolute part of the style. Ovules sub- horizontal; biseriate; anatropous.

Fruit non-fleshy; an aggregate. The fruiting carpel dehiscent; a follicle (the 5 follicles stellately spreading, ventrally sutured). Dispersal unit the seed. Fruit 10–25 seeded (per follicle). Seeds long and broadly winged (in the upper part). Cotyledons 2; rolled.

Physiology, phytochemistry. Saponins/sapogenins present (the powdered bark of Q. saponaria being used as a substitute for soap).

Geography, cytology. Neotropical. Temperate to sub-tropical. Brazil (Q. brasiliensis), Andean Chile and Peru (Q. saponaria). Supposed basic chromosome number of family: 14.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Rosales. Cronquist’s Subclass Rosidae; Rosales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Fabales.

Species 2. Genera 1; Quillaja.

Economic uses, etc. Known as the Soap or Soapbark Tree.

History of the encoded description. This draft description by LW (2009) lacks information on anther development and pollen, embryology, and phytochemistry. It also needs pursuing further with special reference to features characteristic of Rosaceae.

Illustrations. • Quillaja brasiliensis: Fl. Brasil. 14 (1867–72). • Quillaja saponaria: Bot. Mag. 123 (1897). • Quillaja saponaria, vegetative: © Zoya Akulova (2016). • Quillaja saponaria, fruit: © Zoya Akulova (2016).

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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