Hibbertia Andrews

Scientific Description

Family Dilleniaceae.

Habit and leaf form. Small shrubs. Plants with neither basal nor terminal concentrations of leaves. Mesophytic, or xerophytic. Leaves alternate; spiral; leathery, or ‘herbaceous’; subsessile to sessile; sheathing, or non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades entire; flat, or rolled, or solid; terete; one-veined, or pinnately veined, or palmately veined. Leaves with stipules, or without stipules. Leaf blade margins entire, or crenate, or serrate. Leaves without a persistent basal meristem. Stem anatomy. Nodes unilacunar, or tri-lacunar, or penta-lacunar to multilacunar.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers solitary (usually, terminating small axillary shoots or appearing axillary in a tuft of floral leaves), or aggregated in ‘inflorescences’; when aggregated, in spikes. The terminal inflorescence unit cymose, or racemose. Flowers small to large; regular to somewhat irregular. The floral asymmetry when noticeable, involving the androecium (the stamens sometimes all on one side of the carpels). Flowers partially acyclic. Floral receptacle not markedly hollowed. Free hypanthium absent. Hypogynous disk absent. Perianth with distinct calyx and corolla; 10. Calyx 5; more or less gamosepalous (basally); spreading; spirally imbricate; persistent. Corolla 5; polypetalous; imbricate, or crumpled in bud; yellow, or orange. Corolla members bilobed, or entire. Androecium 5–100. Androecial members branched (the filaments often in fascicles for at least part of their length), or unbranched. Androecial sequence determinable, or not determinable. Androecial members when numerous, maturing centrifugally (as a whole, or those within each cluster); free of the perianth; all equal to markedly unequal; free of one another, or coherent (often united basally); when clustered 2–5 - adelphous (sometimes with additional free stamens). Androecium exclusively of fertile stamens, or including staminodes. Staminodes 1–22. Stamens 5–100; isomerous with the perianth to polystemonous. Anthers basifixed, or adnate; dehiscing via pores to dehiscing via short slits (apically), or dehiscing via longitudinal slits; introrse, or latrorse; tetrasporangiate. Gynoecium 2–5 carpelled (or more). The pistil 2–5 celled (or more). Gynoecium apocarpous to syncarpous; eu-apocarpous, or semicarpous (then carpels shortly connate on their inner edge); superior. Carpel stylate; apically stigmatic; 1–8 ovuled. Placentation when apocarpous marginal, or basal. Ovary plurilocular; when syncarpous 2–5 locular (or more). Styles 2–5 (or more); when carpels connate, free. Stigmas wet type; non-papillate; Group IV type. Placentation when syncarpous axile, or basal. Ovules when syncarpous, 1–8 per locule; ascending; apotropous; with ventral raphe; arillate; anatropous to amphitropous (? with zigzag micropyle).

Fruit and seed features. Fruit non-fleshy; an aggregate. The fruiting carpel a follicle, or an achene. Seeds reniform to globular; copiously endospermic. Endosperm oily. Embryo well differentiated (very small). Cotyledons 2.

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