This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The seeds of this plant which have been discovered in Interglacial deposits are both characteristic and in good condition. It ranges from Arctic Europe, W. Asia, W. Persia, and has been introduced in North America. It occurs in 96 vice-counties, everywhere but in the W.S.N. Highlands (except Clyde Islands), and in the Northern Isles, making 97, that is, from Inverness southward, probably in each case naturalized, and elsewhere as an escape. It is found in Ireland and the Channel Islands. Watson considered it a denizen.
No doubt the Greater Celandine owes its distribution very largely to former uses to which it was put, e.g. to heal the eyes, and one may usually find it hiding beneath the hedge surrounding the cottage garden in the country or near a village. It is always found where there has been some human habitation at one time or another. In the same way it is one of the plants to be found on waste ground with poppies, vetches, and other casual plants, and amongst ruins.
The Greater Celandine is a leafy plant, with leaves with lobes each side of a common stalk, rounded lobes, and rather slender stems, succulent and full of juice, easily broken, hence perhaps its choice of shelter under hedges, etc. It grows erect, and were its petals not so small might be taken for a yellow poppy. The juice serves to protect the plant from animals. Buds may be produced from the margin of the leaf.
The leaves and stem are roughly hairy, and somewhat bluish-green, the leaf-stalk enlarged at the base. The flower-stalk is umbelled, and the capsules are linear, long, and contracted. Chelidonium refers to the supposed coincidence between its time of flowering and the swallow's appearance. The black seeds are shining with longitudinal rounded ridges.
Greater Celandine is usually about 2 ft. high. It flowers from May to August, and is a perennial, deciduous, and herbaceous plant.
When the flower opens the anthers open in the sun laterally, and the stigma also matures. It is taller than the anthers, so that insects alighting in the centre must first touch it and promote cross-pollination, while those that alight on the petals may cause cross- or self-pollination. The anthers close up in dull weather, and the stamens open inwardly and cause thereby self-pollination. No honey is produced, so that insects are pollen-seekers.
The Greater Celandine is dispersed by its own agency. The pods readily open, and are jointed, and distribute the seeds around the parent plant. It is also dispersed by ants, the elaiosomes containing nutritive matter.
Photo. Flatters & Garnett - Greater Celandine (Chelidonium Majus, L.)
This is a sand-loving plant, requiring a sand soil, and also in part a humus-loving plant, needing a slight amount of humus soil.
No fungal pests are known. The visitors are Lepidoptera, Large Ranunculus (Polia flavocincta), Small Angle Shades (Euplexia lucipara), Tortrix semialbana; Homoptera Aleurodes proletella and Siphonophora chelidonii; Hymenoptera (Apidae), Bombus pratorum, B. agrorum, B. rajellus, Halictus cylindricus, H. zonulus, H. sexnotatus; Diptera (Syrphidae), Syrphus balteatus, S. ribesii, Syritta pipiens, Ascia poda-grica, Rhingia rostrata; Empidae, Empis livida.
Dioscorides gave the name Chelidonium, which is derived from the Greek chelidon, a swallow, in allusion to its flowering when these birds appear; and majus is Latin for greater.