Citriobatus Loudon

Scientific Description

Family Pittosporaceae.

Habit and leaf form. Shrubs; evergreen. Plants spiny (on branchlets, sometimes lateral spines present). To 1–8 m high. Mesophytic. Not heterophyllous. Leaves small; alternate (clustered on knob-like short shoots); petiolate; simple. Leaf blades dorsiventral; entire; ovate, or obovate, or oblong, or elliptic, or obtriangular, or orbicular. Mature leaf blades adaxially commonly glabrous, or pubescent (sparsely hairy); abaxially commonly glabrous, or pubescent (sparsely hairy). Leaf blade margins entire, or serrate (or lobed).

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

Inflorescence and flower features. Flowers solitary (mostly on knob-like short shoots provided with small imbricate bracts); axillary; usually sessile, or pedicellate (rarely); bracteate; small; regular; 5 merous; tetracyclic. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; polysepalous (slighlty unequal); hairy (shortly fimbriate or ciliate); imbricate; exceeded by the corolla. Corolla present; 5; 1 -whorled; polypetalous (coherent at the base to form a more or less definite corolla tube, petals spreading or recurved); imbricate; regular; plain; white, or cream. Androecium present. Androecial members definite in number. Androecium 5. Androecial members free of the perianth; free of one another. Stamens 5; becoming exserted; all more or less similar in shape; isomerous with the perianth; oppositisepalous; all alternating with the corolla members. Anthers all alike; almost basifixed; dehiscing via longitudinal slits; tetrasporangiate. Gynoecium 1 carpelled. The pistil 1 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary unilocular (with 2–5 placentas); 1 locular; sessile, or stipitate (shortly). Ovary summit hairy, the hairs not confined to radiating bands. Gynoecium stylate. Styles 1; persistent; hairless. Stigmas 1. Placentation parietal. Ovules in the single cavity 10–50 (i.e. ‘few’ to ‘many’).

Fruit and seed features. Fruit 4–25 mm long; fleshy (pericarp thin or hard); yellow, or orange; not hairy; indehiscent; a berry. Dispersal unit the seed. Fruit 5–50 seeded (i.e. few to ‘many’). Seeds mucous (often immersed in a mucilaginous pulp); small.

Geography, cytology, number of species. World distribution: Australia and Malesiana. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Queensland, and New South Wales. Northern Botanical Province. A genus of 5 species; 1 species in Western Australia; 0 endemic to Western Australia.

Etymology. From the Greek for "citron tree" and "any prickly bush"; name derived from the common name in Queensland: orange thorn.