| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Cleomaceae (Pax) Airy Shaw

~ Capparidaceae.

Including Cleomaceae Horan. (p.p.)

Habit and leaf form. Herbs (mostly), or shrubs (a few), or trees (a few), or lianas (a few); glandular, resinous. Annual (mostly), or perennial. Self supporting, or climbing (a few). Leaves alternate; spiral; petiolate; non-sheathing; aromatic, or without marked odour (?), or foetid; compound; unifoliolate (rarely, the leaves ‘simple’), or ternate, or palmate ((1–)3–7 foliolate); stipulate. Stipules scaly, or leafy, or spiny.

Leaf anatomy. The leaf lamina dorsiventral to centric. Abaxial epidermis papillose, or not papillose. Stomata present; anomocytic. Hairs present, or absent; commonly glandular (by contrast with Capparidaceae). Minor leaf veins without phloem transfer cells (Cleome, Isomeris).

Axial (stem, wood) anatomy. Secondary thickening developing from a conventional cambial ring.

The vessel end-walls simple. The parenchyma paratracheal.

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

Inflorescence, floral, fruit and seed morphology. Flowers somewhat irregular to very irregular. Floral receptacle developing a gynophore, or developing an androphore and developing a gynophore. Hypogynous disk present.

Perianth with distinct calyx and corolla; (4–)8(–12); 2–3 whorled (more or less resolvable into K2+2 C4 with decussate calyx and diagonal petals, cf. Cruciferae, or only theoretically so). Calyx (2–)4(–6); 1 whorled, or 2 whorled; polysepalous, or gamosepalous; persistent, or not persistent; imbricate, or open in bud. Corolla (2–)4(–6); 1 whorled; polypetalous, or gamopetalous (connate or not). Petals clawed.

Androecium 4–100 (the four primordia often branching to give many stamens). Androecial members branched (from 4 primordia), or unbranched; when many/branched, maturing centrifugally; free of the perianth; united with the gynoecium (fused to the gynophore), or free of the gynoecium; all equal, or markedly unequal. Androecium exclusively of fertile stamens, or including staminodes. Stamens 4–50; tetradynamous (rarely), or not didynamous, not tetradynamous; basically oppositisepalous (i.e. considering the primordia). Anthers dehiscing via longitudinal slits; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; (2–)3(–4) aperturate; colporate; 2-celled.

Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular, or 2 locular (with a replum). Locules secondarily divided by ‘false septa’ (the replum), or without ‘false septa’. Gynoecium transverse; stylate, or non-stylate to stylate. Styles 1; apical. Stigmas 1; dry type; papillate; Group II type. Placentation parietal (the two placentas longitudinally divided by a replum, cf. Cruciferae). Ovules in the single cavity 10–100 (to ‘many’); 10–50 per locule (‘many’); campylotropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped (with diverging tips), or hooked. Endosperm formation nuclear. Embryogeny onagrad.

Fruit non-fleshy; dehiscent; a silicula, or a siliqua. Capsules valvular (the two valves separating from the persistent replum, by contrast with capsular Capparidaceae). Seeds scarcely endospermic, or non-endospermic. Cotyledons 2. Embryo chlorophyllous (1/1); curved, or bent. The radicle lateral, or dorsal.

Physiology, phytochemistry. C3, or C4. C3 physiology recorded directly in Cleome. C4 physiology recorded directly in Gynandropsis. Anatomy C4 type (Gynandropsis), or non-C4 type (Cleome). Mustard-oils present. Cyanogenic, or not cyanogenic. Alkaloids absent. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin, or quercetin. Ellagic acid present (Cleome gigantea), or absent (C. spinosa, Polanisia). Aluminium accumulation not found.

Geography, cytology. Sub-tropical and tropical. Widespread tropical and subtropical.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Violiflorae; Capparales. Cronquist’s Subclass Dilleniidae; Capparales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Brassicales.

Species 275. Genera about 8; Buhsia, Cleome, Cleomella, Gynandropsis, Haptocarpum, Physostemon, Polanisia, Wislizenia.

General remarks. The descriptions compiled here depict Cleomaceae differing from Capparidaceae (q.v.) mainly in having leaves with resinous glandular hairs, the ‘cruciferous’ ovary and fruit (placentation with a replum, and silicula or siliqua), and in being positive for flavonols but lacking alkaloids. However, the separation may be unsustainable, since precise comparative data on gynoecium and fruit structure are elusive or non-existent, and difficulties are encountered in assigning genera to one family or the other.

Illustrations. • Le Maout and Decaisne: Cristatella (~Polanisia), Cleome. • Cleome atropurpurea (as C. dendroides): Bot. Mag. 61 (1834). • Cleome lanceolata, as Physostemon: Martius, Nova Gen. et Spec. Pl. Brasiliensium (1824). • Cleome lutea: Bot. Reg. 67, 1841. • Cleome rosea: Bot. Reg. 960, 1826. • Cleome speciosa (as C. speciosissima): Bot. Reg. 1312, 1830. • Cleomella arborea (as Isomeris): Bot. Mag. 67 (1840). • Cleomella mexicana: Hook. Ic. Pl. 1 (1837). • Physostemon lanceolatum: Lindley. • Polanisia hirta: Thonner. • Polanisia chelidonii, cf. Cleome: Wight’s Figs. of Indian Plants 2 (1843).

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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