Kindly sponsored by
a member of the International Dendrology Society
Julian Sutton (2023)
Sutton, J. (2023), 'Anthyllis' from the website Trees and Shrubs Online (treesandshrubsonline.
A genus of about 23 species of shrubs, herbaceous perennials and annuals native to Europe, W Asia, N & E Africa, and Macaronesia. Leaves imparipinnate, rarely simple or trifoliate. Stipules small, falling early. Flowers in dense heads, solitary or in small axillary groups. Calyx tubular or campanulate, toothed. Corolla with 5 lobes (banner, 2 wings, 2 forming the more or less beaked keel). Stamens 10, the filaments of all united to form a tube (sometimes one upper stamen free for up to half its length). Fruit a legume, without constrictions between the seeds; often indehiscent or only tardily dehiscent, usually included within the persistent calyx. (Tutin et al. 1968).
Anthyllis is very much a Mediterranean genus. Only a fraction of the species are woody, most of them only marginally hardy in our area. Those which are need well drained, sunny, sheltered positions and do not require fertile soil. The remainder are herbaceous perennials, annuals, or subshrubs with herbaceous stems from short woody bases. A very few species extend beyond the Mediterranean into the Alps, and to the Arabian Peninsula and East Africa.
Anthyllis belongs to Tribe Loteae of the Fabaceae, along with genera such as Lotus, Hippocrepis and Coronilla. Like Lotus, its fruits are non-lomentaceous, that is they are not made up of single-seeded sections with seedless constrictions between. Unlike all these genera, the filaments of all 10 Anthyllis stamens (rather than just 9) are united to form a tube (occasionally the 10th may be free for part of its length). The persistent calyx, which becomes more or less inflated after the petals fall, enclosing the fruit, is perhaps the most distinctive diagnostic feature in the garden (Bean 1976). The most thorough molecular study to date suggests that Anthyllis is a natural, monophyletic genus, perhaps sister to the tropical African genus Antopetitia (Degtjareva et al. 2012).
Flowers – in shades of yellow or red/purple – are the Kidney Vetches’ major attraction. The general appearance of a flowering specimen depends on the type of inflorescence. Some species (eg. A. barba-jovis) have dense terminal heads, while in others (eg. A. hermanniae) they are scattered across the plant in small axillary clusters. The typical peaflower structure is usually associated with pollination by bees of various sorts, and this is true of Anthyllis where investigated (Benelli et al. 2017). The fused stamens surround the style, together making a brush enclosed within the two partially fused lower petals (the keel). There are two lateral petals (the wings) and a larger, hooded upper petal (the banner or standard). The weight of a visiting bee separates the keel petals, pushing anthers and stigma up against the insect’s body.
We describe just three species, the shrubby, creamy yellow-flowered, but tender A. barba-jovis; the somewhat hardier, rather spiny, bright yellow A. hermanniae; and the still hardier but only subshrubby A. montana, a smaller alpine plant with reddish-purple flowers, in scale for the rock garden. A few other woody species seem not be be grown in our area. A. cytisoides L. (S&E Spain, Balearic Islands, S France) is an erect shrub to 60 cm with 1–3-foliate leaves, no spines, and yellow flowers in 1–3-flowered axillary clusters (Tutin et al. 1968). A. terniflora (Lag.) Pau (S Spain, Morocco) is similar but less robust, with only unifoliate leaves (Tutin et al. 1968). A. hystrix (Willk. ex Barceló) Cardona, J.Cont. & E.Sierra (endemic to Minorca) is a densely spiny shrub with yellow flowers in groups of up to 6 (Brullo & del Galdo 2006). The entirely herbaceous A. vulneraria L., with a wide range across Europe, is common in gardens.
Propagation is usually by seed, although more tender species might not set seed near the limits of hardiness. Semi-ripe cuttings taken in late summer may be rooted in an enclosed propagator (Huxley, Griffiths & Levy 1992; Bean 1976).