Charles Darwin called the evolution of flowering plants, or angiosperms, an “abominable mystery”. With between 250,000 and 400,000 species, they they make my mind boggle.
Scientists are trying to solve this mystery by sequencing the genome of a plant called Amborella trichopoda, a rare understorey shrub from New Caledonia in the Pacific Ocean. The genetic makeup of this plant is important because it is understood to be the earliest relative, in evolutionary terms, of all the flowering plants.
Amborella is quite rare in cultivation and by no means hardy for British gardens. However there are some other plants that come very close, in evolutionary terms, which you can grow here. Amborella is placed by scientists in a group of plants called the basal angiosperms. This group also contains amborellas’ closest relatives, the waterlilies (nymphaea), and another group of plants called the Austrobaileyales, which contains a genus called illicium.
Illiciums first evolved in the Cretaceous period around 100 million years ago, while dinosaurs still roamed the earth. They are a group of around 30 species of small trees and shrubs from North America, the Caribbean and Asia. Illiciums may not be instantly recognisable to you under their botanical name, but I am sure you will recognise them when I say that the spice star anise is the seed pods of one species called Illicium verum. Not all, however, can be used as a spice, and the red-flowered I. floridanum from the USA is very poisonous.
I. floridanum and its close relative I. mexicanum are unusual for illiciums in that they will stand being grown in brighter conditions. Illiciums evolved to grow in the dark conditions of the conifer forests of the Cretaceous and most of them suffer significant leaf chlorosis, yellowing of the foliage, and death if exposed to too much sun.
Species such as I. henryi definitely need to be grown in full shade, which for me is a good enough reason to grow this demure shrub. With its nodding coral flowers and evergreen waxy foliage it doesn’t scream look at me but sits shyly in the shadows waiting its turn. I. simonsii, however, cannot be missed. This small conical tree likes a cool spot in the garden and flowers profusely with buttermilk blossoms from a young age. Flowering alongside the rhododendrons and camellias in March and April, it has the added bonus of fragrance and, if grown in a group, wacky star anise-like, spiky seed pods in early autumn.
Illicium verum, anisatum and lanceolatum all have clearer, paler flowers than those of simonsii and they flower just as early in the year. Smaller in stature too, they are all delicately beautiful medium-sized shrubs in a British garden. However, if you want something a little bigger, look out for I. majus and griffithii. Though both are good-sized trees in their native Himalayas, they are proving not to get so big in cultivation. They aren’t as floriferous as their relatives, but when they do flower, it’s a treat. With large waxy leaves and gobstopper-like rosy pink flowers, they are really quite a special addition to a garden. I hope my I. majus flowers for me this year.
I grow a number of different species of illicium in my Fossil Garden at home. I love them for their evergreen foliage and interesting flowers in colours from deepest red through yellow to pure white. Yet it’s what they represent, those earliest days of the evolution of the flower, that I love the most: 100 million years of time that I can see blooming in my garden.
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