Harrisonia A.Juss.

Reference
Mém.Mus.Hist.Nat. p517 (1825)
Name Status
Current

Scientific Description

Family Simaroubaceae.

Habit and leaf form. Small trees, or shrubs. Leaves cauline. Stem internodes solid. Mesophytic. Leaves alternate (clustered sometimes); spiral; petiolate; non-sheathing; not gland-dotted; compound; ternate (trifoliate); imparipinnate. Leaflets elliptic to ovate. Leaf blades pinnately veined; cross-venulate. Leaves with stipules, or without stipules (sometimes). Stipules when present, intrapetiolar; spiny (or conical or somewhat recurved); caducous. Leaf blade margins entire, or serrate (irregularly). Leaves without a persistent basal meristem. Leaf anatomy. Hairs present. Extra-floral nectaries absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

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

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; cymes few-flowered. Flowers sessile; bracteate; ebracteolate; small; regular; 4 merous, or 5 merous; cyclic; pentacyclic. Floral receptacle developing an androphore, or developing a gynophore, or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk present; extrastaminal. Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; isomerous. Calyx present; 4–5; 1 -whorled; gamosepalous; blunt-lobed; imbricate, or valvate; regular. Calyx lobes triangular. Corolla present; 4–5; 1 -whorled; polypetalous; imbricate (slightly); regular; green (green-white), or yellow. Petals more or less elliptic, or ovate to oblong. Corolla members minutely ciliolate. Androecial members definite in number. Androecium 8, or 10. Androecial members free of the perianth; all equal; free of one another; 2 -whorled. Androecium exclusively of fertile stamens. Stamens 8, or 10; all more or less similar in shape; diplostemonous; oppositisepalous. Filaments appendiculate. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 4–5 carpelled. The pistil 5 celled, or 5 celled. Carpels isomerous with the perianth, or increased in number relative to the perianth. Gynoecium syncarpous; synovarious to eu-syncarpous; superior. Ovary plurilocular; 4 locular, or 5 locular. Gynoecium stylate. Styles 4–5; free, or partially joined; lateral, or ‘gynobasic’. Placentation axile. Ovules 1 per locule; pendulous; epitropous; with ventral raphe (the micropyle superior); hemianatropous to anatropous.

Fruit and seed features. Fruit fleshy (K), or non-fleshy (K); an aggregate, or not an aggregate; indehiscent, or a schizocarp. Mericarps if schizocarpic comprising drupelets. Fruit when not schizacarpous, a drupe. Gynoecia of adjoining flowers combining to form a multiple fruit (A). Fruit 2–5 seeded (pyrenes). Seeds more or less non-endospermic. Cotyledons 2 (large, expanded). Embryo straight, or curved.

Etymology. After Charles Harrison who wrote a book on fruit trees, published in 1825.

J. Gathe and Leslie Watson, 8 September 2016

Taxonomic Literature

  • 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.
  • Australia. Bureau of Flora and Fauna (1985). Flora of Australia. Volume 25, Melianthaceae to Simaroubaceae. Australian Govt. Pub. Service. Canberra.