Aphanes L.

Scientific Description

Common name. Parsley-piert. Family Rosaceae.

Habit and leaf form. Herbs. Plants unarmed. Annual. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves; to 0.02–0.3 m high. Mesophytic. Not heterophyllous. Leaves minute, or small; not fasciculate; alternate; spiral; not decurrent on the stems; ‘herbaceous’; imbricate, or not imbricate; petiolate, or subsessile, or sessile. Petioles wingless. Leaves non-sheathing; simple; epulvinate. Leaf blades dissected; flat; orbicular; palmately lobed, or much-divided; palmately veined; without cross-venules; attenuate at the base. Mature leaf blades pilose. Leaves with stipules. Stipules intrapetiolar; adnate to the petiole; concrescent; leafy (lower part membraneous). Leaf blade margins entire; not prickly; flat, or revolute (slightly). Vegetative buds scaly. Leaves without a persistent basal meristem. Vernation conduplicate. Leaf anatomy. Hairs present; glandular hairs absent. Unicellular hairs present. Complex hairs absent. Branched hairs absent. 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. Plants not viviparous; homostylous. Floral nectaries present. Nectar secretion from the disk. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; not crowded at the stem bases. Inflorescence few-flowered. Flowers not in pairs subtended by a common bract; in cymes. Inflorescences compound. The terminal inflorescence unit cymose. Inflorescences axillary, or leaf-opposed; ascending. Flowers subsessile, or sessile; small; regular; 4(–5) merous. Floral receptacle markedly hollowed. Free hypanthium present; urceolate; extending beyond ovary. Hypogynous disk present; extrastaminal; annular. Perianth sepaline; 4(–5); 1 -whorled. Calyx present; 4(–5); 1 -whorled; gamosepalous; toothed. Calyx lobes markedly shorter than the tube. Calyx segments entire. Calyx slightly spreading; glabrous; valvate; urceolate; regular; green, or yellow; non-fleshy; persistent. Calyx lobes triangular. Epicalyx absent, or present (but minute). Corolla absent. Androecium present. Androecial members definite in number. Androecium 1(–2). Androecial members free of the perianth; all equal; free of one another; 1 -whorled. Stamens 1–2; attached on the rim of the hypanthium; all more or less similar in shape (when more than one present); reduced in number relative to the adjacent perianth; inflexed in bud. Filaments not geniculate; glabrous; cylindrical. Anthers all alike (when more than one present); dorsifixed; versatile; dehiscing via longitudinal slits; extrorse; tetrasporangiate. Gynoecium 1–2 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium monomerous, or apocarpous; of one carpel, or eu-apocarpous; superior. Carpel stylate. Style straight. Carpel 1 ovuled. Placentation apical. Ovary stipitate. Styles simple; becoming exserted, or not becoming exserted; hairless. Stigmas peltate (discoid). Ovules ascending; non-arillate; orthotropous.

Fruit and seed features. Fruit non-fleshy; not hairy; not spinose. The fruiting carpel indehiscent; an achene. Fruit 1 celled. Endocarp not ribbed. Dispersal unit the fruit. Fruit 1 seeded. Seeds 1 per locule. Seeds non-endospermic; small. Cotyledons 2; flat. Testa hard; smooth.

Geography, cytology, number of species. World distribution: this genus has a disjunct distribution including Europe, North Africa, central and western Asia, Atlantic islands, eastern and western North America, south-western South America, eastern coast South America and Australia. Native of Australia, or adventive. Not endemic to Australia. Australian states and territories: Western Australia (naturalised only), or South Australia, or New South Wales, or Victoria, or Australian Capital Territory, or Tasmania. South-West Botanical Province. X=8; ploidy levels recorded 6 (but could be higher). A genus of ca. 20 species; 1 species in Western Australia; Aphanes arvensis L.; 0 endemic to Western Australia.

Economic uses, etc. Reported to be useful in the treatment of bladder problems.

Etymology. From the Greek aphanes, "obscure, inconspicious", referring to the flowers and to the general nature of the plant.