Scilla verna is a small plant (15 cm) over-wintering below ground as a bulb. First it produces a few strap-like leaves, only 3-6 of them, and then come the flowers. There are up to 12 flowers per plant, each having six ‘petals’. Strictly speaking these are neither petals nor sepals but petal-like structures called ‘tepals’ (in older floras we see the less poetic term ‘perianth segments’). The anthers are violet-blue. When viewed from above the general appearance of the flowers is one of blue stars in a sea of green spaghetti (see my picture below).
Scilla verna, showing its strap-like leaves and blue flowers. Photo: John Grace
Spring squill grows on wind-swept sea cliffs and other coastal habitats, mostly in the West of Britain. The pale blue flowers appear in the spring. The plant is found in maritime heath, forming loose clumps, interspersed with other species such as Heather, Wild Thyme, Bird’s-foot Trefoil and Sea Plantain, with grasses including Sheep’s Fescue and Yorkshire Fog. Like many other species that arise from bulbs it develops its leaves and flowers rather quickly. This year, I visited a place where I knew it would duly appear, at Maidens in Ayrshire. I went every two weeks from late March, searching in vain for the appearance of leaves. No luck, but last week I was rewarded with the flowers in their full glory.
S. verna patch on a cliff – not a big cliff but a cliff nevertheless, Maidens, Ayrshire. Photo: John Grace
This rapid development of leaves and flowers from bulbs was noted by Grime and Mowforth (1982) and widely discussed. It is associated with a very high genome size. It turns out that the cells for the next year’s growth are already formed before winter begins. To develop in spring, the cells are simply inflated with water, avoiding the likely delay in cell divisions (mitosis) at a cold time of year, the spring.
Co-existing with Ranunculus bulbosus and Festuca ovina. Photo: John Grace
It’s a pretty plant, one often grown in rock gardens. It is considered to be a native to our British Islands, and was first recorded in the wild in 1641 (in Dublin!). It has been cultivated at Kew Gardens since 1789. Seeds and bulbs can be purchased from many specialist suppliers. You can expect to see a Scilla in a botanic garden near you. But hurry, the flowers do not last very long. And the Scilla you see could be a different species – there are more than 50 of them native to Europe.
Earlier floras placed Scilla with the lilies in the Liliaceae. It may come as a surprise that Scilla now belongs to the asparagus family, the Asparagaceae. Its DNA reveals its strong relationship to asparagus and not to lily, even though the plant looks like a small lily. Of course, it can be annoying for people who write books or teach botany, or make garden labels, to find they must update their material. The delicate issue of where any plant belongs in the tree of life is decided by a body of folk called the Angiosperm Phylogeny Group (APG), and they said in 2009 that Scilla belongs with bluebells in one of seven subfamilies of the Asparagaceae called the Scilloideae. When my asparagus plants develop flowers I will look at their structures with renewed interest.
Another species of Scilla, this time at the Royal Botanic Garden of Edinburgh. Note the label, the old family name Hyacanthaceae remains on display. Photo: John Grace
I do like browsing the older publications as they give more detail than the modern ones. The Student’s Flora of the British Islands was published in 1884. Its author Joseph Dalton Hooker writes far more about Scilla verna than we find in recent floras. On habitat, he says ‘Rocky pastures, rare. W. coast of England and Wales from Flint to Devon; Scotland from Ayr and Berwick to Shetland; E. and N.E. Ireland, very rare; fl. April-May, – bulb as large as a hazel-nut. We may compare this with the BSBI’s current map. The plant hasn’t changed its distribution much.
S. verna, distribution in Britain and Ireland, from the BSBI records.
The abbreviation Huds. after the species name denotes that the person who first properly described and named the species was William Hudson (1730-1793), a man from Kendal who was apprenticed to an apothecary in London before becoming resident sub-librarian of the British Museum. In 1761 Hudson was elected a Fellow of the Royal Society, and in the following year published his Flora Anglica which was said to “mark the establishment of Linnean principles of botany in England.”
References
Grime JP and Mowforth MA (1982) Variation in genome size – an ecological interpretation. Nature 299, 151-153.
Hooker JD (1884).Student’s Flora of the British Islands. Macmillan, London.
John Grace©
Botany in Scotland 