Common name : Winter heliotrope
Latin name : Petasites pyrenaicus
Member of the Daisy family (Asteraceae)
Midwinter in Seaford and in St Leonard’s churchyard there are several large patches of bright green foliage covering the ground.(fig 1).
Each leaf is almost a complete disc with a narrow gap cut out. (inset to figure 1) Looking closely, the edge of the blade is finely serrated. This is Winter Heliotrope.
The leaf stalk is attached at the apex of this cut out area (or “sinus”) of the leaf blade. Underneath the leaf is hairy. The rather sparsely produced flowering stems are stout stalks with multiple daisy-type flower-heads (fig 2). Both the flowering stalks and the leaves arise direct from the ground and sprout from underground stems (“rhizomes”) which also produce the roots.
Winter Heliotrope can be found in many places in and around Seaford, both in and out of gardens. It was not native to British Isles but was introduced by the 18th century and is now well naturalized. So, while many examples will be garden escapes or even deliberately planted, it is included on recording lists as a wildflower. Its original home is in North Africa and Southern Europe. You will see it all over Sussex and the south of England but it is more localized as you travel further north. This distribution is similar in continental Europe.
The wide distribution away from its origin is really quite remarkable because the plants we see do not produce any seeds. Just as a Dandelion will regrow from a fragment of its tap root, so will this plant regrow leaves, roots and flowers from a fragment of the rhizome. Before the days of Garden Waste collections, dug up garden weeds were disposed of in many casual ways and hence the species has become widely dispersed.
Thus the flowers deserve a closer look. It turns out that, while in its native home, the plants are dioecious (male or female), those in British Isles are only ever MALE. You won’t find the females here at all and, even where they do occur in Africa and southern Europe, they are less common than males.
They are in the daisy family (Asteraceae). A typical daisy “flower” is, of course, a cluster of little flowers or florets. (fig 3)
The florets are of two types … the ray florets which are a flattened tongue shape or ligules (the white ones in this lawn daisy) and the yellow central disc florets which are tubular shaped. Some species have only one or other type (e.g. Dandelions only have ray (ligulate florets).[1]
Either type of floret can be male, female or bisexual depending on the daisy species. However, being a male flower, does not exclude having some female parts, but they do not function.
Figure 4 shows a close up of a flower head with a labelled copy marking the ray (ligule) and disc (tubular) florets. In the very centre, are a cluster of unopened disc florets.
Figure 5 shows, from the left, a mixture of individual florets.
- A ray floret
- An unopened disc floret
- 5. are opened disc florets
- is a partially dissected flower head.
The dark structures that protrude from the disc florets are (male) anthers and the white structure poking up above them is a (female but non-functioning) pistil coated in pollen. Also note that when the disc florets open the tubular structure is obvious with an upper rim composed of 5 curled back
pointed tips. These are the unfused tips of the 5 petals that have formed the tube.
At the base of each floret there is what looks like a seed but it is sterile and at the junction of the “seed and the floret tube there are some hairs similar to the parachute hairs of a Dandelion clock (“pappus”). These, too, have no function and in time the whole flower dies back. I find the whole structure quite attractive, especially in those flowers which have purple petals. (Figure 6).
Readers will have realised that I am a “names” nerd. “Heliotrope” means “grows towards the sun”. “Opens in the sun” would be better. Like Dandelions, the flower heads begin to close up once brought indoors.
Also, in many books, you will find the Latin name given as Petasites fragrans but recent research has been accepted as showing that the species epithet pyrenaicus has precedence, having been used by Linnaeus (see our pages on Botanical Latin). There are other introduced Petasites spp that have naturalized, but they are much less frequent. If found, they are most likely garden throw-outs. . Our native Petasites is Butterbur, Petasites hybridus, but that is a plant of Northern England and it is rated as scarce in Sussex. Watersides like Amberly Brooks and Pulborough are recorded sites and perhaps one should be checking out the new wetland around the Cockshut at Lewes?
Brian Livingstone
* In this context of daisy florets, the terms ray and ligulate tend to be used interchangeably as do disc and tubular.
