Synonyms: Pararistolochia APNI*
Description: Slender or robust vines, or (not in N.S.W.) erect, climbing or twining herbs or shrubs. Young branches ± glabrous to rusty-pubescent. Roots fibrous or tuberous.
Leaves entire, often coriaceous; venation often conspicuous; petiole often thickened and twisted, with base expanded into a horizontal ridge extending around the stem; pseudo-stipules absent or sometimes present.
Inflorescences few-flowered racemes or clusters or flowers solitary; axillary or leaf opposed. Flowers bisexual, zygomorphic or rarely actinomorphic, usually fetid. Calyx usually petaloid, tubular at least below; tube straight to sigmoid, inflated basally forming utricle that encloses sexual organs, then constricted before expanding (occasionally only slightly) into limb; 1–3-lobed or lobeless. Petals absent (in Australia). Anthers 6–24, sessile, entirely united with dorsal side of stigma (including stigmatic lobes). Ovary inferior, 6-locular; stigmatic lobes 6 or (not in Australia) up to 12.
Fruit a septicidally dehiscent capsule (usually dehiscing upwards from the base and closed at apex, pedicel splitting concurrently), mostly 6-valved; or indehiscent, slightly to strongly 6-ribbed, somewhat fleshy, yellow to orange when ripe. Seeds numerous, dorsiventrally compressed, flat or convex-concave, occasionally with lateral wing; elaiosome present or absent.
Distribution and occurrence: World: 540 spp., trop. & temp. regions. Aust.: 18 sp. (5 naturalized), Qld, N.S.W., N.T., W.A.
Pararistolochia is recognised as a distinct genus in Qld.
Text by Kerry Gibbons, from E.M. Ross, D.A. Halford, Fl. Australia Online [accessed 3 May 2023] and G.J. Harden, Fl NSW. 4 May 2023.
Taxon concept: Australian Plant Census 2018. Distribution and occurrence: Kew Plants of the World Online; Australian Plant Census [both accessed 3 May 2023].
| | Key to the species | |
| 1 | Fruit dehiscent, short; perianth irregular with a single lobe (long lip), or 2-lipped with a broad standard and long keel; stigmatic lobes up to 6; anthers up to 6; flowers borne on leafy shoots | 2 |
| Fruit indehiscent, elongate, strongly ribbed; perianth regularly 3-lobed or irregular with 1 or 3 long tails from the mouth of the limb; stigmatic lobes 6–12; anthers 6–24; flowers mostly on the old wood | 3 |
| 2 | Flowers less than 3 cm across limb | Aristolochia elegans |
| Flowers more than 3 cm across expanded limb
Back to 1 | Aristolochia meridionalis |
| 3 | Leaves mostly 10–20 cm long, ovate to elliptic, base cordate or rounded, brown hairs scattered on veins on lower surface | Aristolochia praevenosa |
| Leaves usually 5–10 cm long, lanceolate to narrow-elliptic, base ± truncate to slightly cordate, glabrous
Back to 1 | Aristolochia laheyana |
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