Habit and leaf form. Under- shrubs; evergreen, or deciduous; bearing essential oils. Stem growth subglobular, exserted, large. Mesophytic, or xerophytic. Leaves scattered; leathery, or ‘herbaceous’; very shortly petiolate; gland-dotted; aromatic; simple (more or less terete). Leaf blades when simple dissected, or entire; when simple/dissected pinnatifid, or much-divided; pinnately veined, or one-veined. Leaves without stipules, or with stipules. Stipules when present, intrapetiolar; represented by glands. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent; complex hairs absent (trichomes simple). Stem anatomy. Nodes unilacunar, or tri-lacunar. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.
Inflorescence and flower features. Flowers usually solitary; terminal; pedicellate (short), or sessile; bracteate; small to medium-sized; fragrant; regular, or somewhat irregular. The floral asymmetry when noticeable, involving the perianth and involving the androecium (not K). Flowers 5 merous; cyclic. Floral receptacle developing a gynophore (associated with the disk), or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk present; intrastaminal; annular (sometimes one-sided), or of separate members. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx 5; 1 -whorled; polysepalous; imbricate; regular; with the median member posterior. Corolla 5; 1 -whorled; polypetalous (corolla cylindrical); imbricate; regular, or unequal but not bilabiate; glabrous abaxially; glabrous adaxially. Petals ovate to oblong. Androecium 10. Androecial members unbranched, or branched (? by the splitting of simple primordia); free of the perianth; all equal, or markedly unequal; coherent; 1 - adelphous (the lower 3/4 united into a narrow cylinder); 1 -whorled, or 2 -whorled. Androecium including staminodes (antisepalous stamens anantherous). Staminodes 5 (slightly exceeding the fertile antipetalous stamens). Stamens 5; becoming exserted; isomerous with the perianth; alternisepalous, or oppositisepalous (? when the outer whorl lost). Filaments hairy (sericeous outside, pilose within). Anthers separate from one another; dorsifixed (included within filaments); versatile; dehiscing via longitudinal slits; introrse, or latrorse; tetrasporangiate; appendaged; minutely apiculate. Gynoecium 5 carpelled; apocarpous (carpels free); eu-apocarpous; superior. Carpel stylate; apically stigmatic (styles affixed near apex of inner margin of carpels, ovary without a sterile apex); (when apo- or semicarpous) (1–)2–100 ovuled. Placentation of the free carpels marginal. Stigmas wet type, or dry type; papillate, or non-papillate; Group II type, or Group IV type. Ovules pendulous to ascending; epitropous; when two or more per cell, collateral, or superposed, or biseriate; arillate, or non-arillate; anatropous, or hemianatropous.
Fruit and seed features. Fruit fleshy, or non-fleshy; an aggregate. The fruiting carpels coalescing into a secondary syncarp, or not coalescing. The fruiting carpel dehiscent, or indehiscent; (when apocarpous) a follicle, or drupaceous, or baccate. Seeds reniform; endospermic, or non-endospermic. Embryo well differentiated. Cotyledons 2. Embryo chlorophyllous, or achlorophyllous; straight, or curved, or bent. Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C3.
Geography, cytology, number of species. A genus of 7 species.