Pityrodia R.Br.
Prodr.Fl.Nov.Holland. 513 (1810)

Name Status: Current
Browse to the list of specimens for Pityrodia R.Br.

Scientific Description
T.R. Lally, Thursday 8 September 2016

Common name. Foxgloves. Family Lamiaceae.

Sometimes included in Chloanthaceae, Verbenaceae.

Habit and leaf form. Perennial shrubs (or undershrubs); evergreen; without essential oils; resinous (viscid or glutinous), or not resinous. ‘Normal’ plants, or ‘normal’ plants to switch-plants (sometimes somewhat switch-plant-like, owing to sparse leaves and broom-like habit). Leaves well developed, or much reduced. Plants unarmed. Leaves cauline. Young stems cylindrical, or tetragonal. Stem internodes solid (woody). To 0.15–3.5 m high. Leaves small to medium-sized; not fasciculate; opposite, or whorled (or scattered); decussate; 3 per whorl; not decurrent on the stems; leathery, or membranous; imbricate, or not imbricate; petiolate, or subsessile, or sessile; aromatic, or without marked odour; simple; epulvinate. Leaf blades entire; flat, or rolled, or solid (sometimes deeply revolute); semi-terete; linear, or lanceolate, or oblong, or ovate; ovate, or elliptic to ovate, or oblong, or obovate, or oblong to obovate, or linear; pinnately veined; cross-venulate. Mature leaf blades adaxially glabrous (and viscid), or pubescent to villous; abaxially woolly (usually). Leaves without stipules. Leaf blade margins entire; flat, or revolute. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present; complex hairs present (sometimes). Complex hairs stellate. Stem anatomy. Secondary thickening anomalous; via concentric cambia.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous, or heterostylous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; axillary. Inflorescence few-flowered. Flowers in cymes, or in racemes, or in panicles. The terminal inflorescence unit cymose. Inflorescences terminal, or axillary; solitary, or in cymes or clusters, axillary or in terminal leafy spikes, racemes or panicles. Flowers pedicellate, or subsessile, or sessile (shortly); bracteate (2 lateral); bracteolate. Bracteoles not adnate to the receptacle. Flowers small to medium-sized; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Perianth members entire. Calyx present; 5; 1 -whorled; gamosepalous; deeply 5- blunt-lobed, or toothed; exceeded by the corolla; cyathiform; regular; non-fleshy; persistent; non-accrescent. Calyx lobes triangular, or ovate (narrow), or linear, or oblong to ovate. Corolla present; 5; 1 -whorled; gamopetalous (5 fused petals); blunt-lobed; imbricate; broad campanulate (tubular below); more or less bilabiate, or unequal but not bilabiate; hairy abaxially (sometimes sparsely and glandular); hairy adaxially (with dense hairy ring around the ovary and sometimes sparsely extends up the anterior lobe); with contrasting markings; white, or pink to white, or purple to blue, or purple to pink, or blue, or orange to red; deciduous. Corolla lobes corolla lobes unequally 5-lobed in upper half, upper lip 2-lobed, lower lip 3-lobed; lobes spreading or those of the upper lip sometimes erect, the anterior larger than the others elliptic, or oblong, or elliptic to orbicular, or orbicular (more or less). Corolla members entire. Androecium present. Androecial members definite in number. Androecium 4. Androecial members adnate (epipetalous); all equal, or markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4. Staminal insertion near the base of the corolla tube, or midway down the corolla tube. Stamens didynamous (somewhat); all more or less similar in shape; reduced in number relative to the adjacent perianth; fertile stamens representing the posterior-lateral pair and the anterior-lateral pair; oppositisepalous. Filaments glabrous; filiform. Anthers dorsifixed; dehiscing via longitudinal slits; bilocular (lobes free and somewhat divergent in the lower halves); appendaged (at the lower end). The anther appendages basal. Gynoecium 2 carpelled. The pistil 4 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious (styles free in upper part); superior. Ovary plurilocular; 2 locular (theoretically), or 4 locular (ostensibly, via false septa). Locules secondarily divided by ‘false septa’. Gynoecium median. Ovary summit hairy, the hairs not confined to radiating bands (or sometimes glandular). Gynoecium stylate. Styles 1; simple; attenuate from the ovary; apical; hairless (glabrous). Stigmas 2; 2 - lobed. Placentation axile. Ovules 2 per locule (theoretically), or 1 per locule (ostensibly, i.e. per locellus); non-arillate; hemianatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; a drupe. The drupes with separable pyrenes (two). Fruit 4 celled; 4 locular. Dispersal unit the mericarp. Fruit 1–4 seeded. Seeds 2 or more per mericarp (2). Seeds endospermic. Embryo straight.

Special features. Calyx limb 5 lobed. Corolla tube exceeding the calyx, or not exceeding the calyx; straight. The upper lip of the corolla incorporating 4 members, the lower 1; (posterior, adaxial) lip of the corolla bilobed; upper (adaxial) lip of the corolla not concave. Lower (abaxial) lip of the corolla 3 lobed; not concave. The anterior pair of stamens often exceeding the posterior pair.

Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. A genus of 41 species; 27 species in Western Australia; 25 endemic to Western Australia.

Etymology. From the Greek for "bran, husk, scale" and "-like"; the leaves of the original species, and most of the others, are scaly.

Taxonomic Literature

  • Shepherd, Kelly A. (2007). Pityrodia iphthima (Lamiaceae), a new species endemic to banded ironstone in Western Australia, with notes on two informally recognised Pityrodia.
  • Wheeler, Judy; Marchant, Neville; Lewington, Margaret; Graham, Lorraine (2002). Flora of the south west, Bunbury, Augusta, Denmark. Volume 2, dicotyledons. Australian Biological Resources Study. Canberra.
  • Rye, B. L.; Trudgen, M. E. (1998). Two new synonyms in the genus Pityrodia (Lamiaceae subfamily Chloanthoideae) [electronic resource].
  • Wheeler, J. R.; Rye, B. L.; Koch, B. L.; Wilson, A. J. G.; Western Australian Herbarium (1992). Flora of the Kimberley region. Western Australian Herbarium. Como, W.A.
  • Marchant, N. G.; Wheeler, J. R.; Rye, B. L.; Bennett, E. M.; Lander, N. S.; Macfarlane, T. D.; Western Australian Herbarium (1987). Flora of the Perth region. Part one. Western Australian Herbarium. Perth.
  • Blackall, William E.; Grieve, Brian J. (1981). How to know Western Australian wildflowers : a key to the flora of the extratropical regions of Western Australia. Part IIIB, (Epacridaceae-Lamiaceae). University of W.A. Press. Perth.
  • Munir, A. A. (1979). A taxonomic revision of the genus Pityrodia (Chloanthaceae).