Dentella J.R.Forst. & G.Forst.

Scientific Description

Family Rubiaceae.

Habit and leaf form. Prostrate herbs (often creeping and rooting at the nodes). Plants succulent, or non-succulent. Perennial. Young stems cylindrical. Self supporting, or climbing. Helophytic, or mesophytic, or xerophytic. Leaves minute to small; opposite (often fascicled on short side branches); petiolate to subsessile; connate (via the stipules), or not connate; gland-dotted, or not gland-dotted; simple; epulvinate. Leaf blades entire; one-veined, or pinnately veined; with indistinct lateral veins. Leaves with stipules. Stipules interpetiolar; somewhat adnate to the petiole (each side); membranous, usually ciliate; with colleters (secreting mucilage), or without colleters. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Domatia not recorded (absent). 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. Plants homostylous, or heterostylous. Entomophilous. Pollination mechanism conspicuously specialized (with passive pollen presentation involving stylar modification), or unspecialized.

Inflorescence and flower features. Flowers solitary; terminal, or axillary (due to sympodial growth, in only one axil of each leaf pair); small to medium-sized; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present, or absent (depending on interpretation); globular, usually hairy. Perianth with distinct calyx and corolla; 10; 2 -whorled; the two whorls isomerous. Calyx 5; 1 -whorled; gamosepalous; deeply lobed; open in bud; shortly tubular; regular; persistent. Corolla 5; 1 -whorled; gamopetalous; lobed. Corolla lobes markedly shorter than the tube (lobes minutely 2–3-toothed). Corolla valvate (induplicate-valvate); narrowly funnel-shaped (tube long); regular; hairy adaxially; white, or pink; deciduous. Androecium 5. Androecial members adnate (to the corolla tube); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion near the base of the corolla tube to in the throat of the corolla tube. Stamens remaining included (usually), or becoming exserted; isomerous with the perianth; oppositisepalous. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen shed in aggregates, or shed as single grains; if aggregated, in tetrads. Gynoecium 2 carpelled. The pistil 2 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious to eu-syncarpous; inferior. Ovary plurilocular; 2 locular. Gynoecium transverse. Epigynous disk present. Gynoecium stylate. Styles 1; simple (filiform); attenuate from the ovary, or from a depression at the top of the ovary; apical; shorter than the ovary at anthesis to much longer than the ovary at anthesis; not becoming exserted (usually), or becoming exserted. Stigmas 1; 2 - lobed (stigmatic lobes linear); wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation axile. Ovules 5–50 per locule (i.e. ‘several’ to ‘many’); pendulous, or horizontal, or ascending; anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; capsular-indehiscent; 2 locular; 1–30 seeded. Seeds endospermic, or non-endospermic. Endosperm ruminate, or not ruminate; if present, oily. Seeds minute. Cotyledons 2. Embryo straight, or curved. Testa reticulate. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Aluminium accumulation demonstrated, or not found.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, Queensland, and New South Wales. Northern Botanical Province and Eremaean Botanical Province.

Etymology. From the Latin for "tooth" and the diminutive suffix -ell-; the corolla-lobes of the original species are denticulate (toothed).