The foxglove is a plant of two summers and one spectacle. In its first year it makes nothing but a flat green wheel of leaves pressed to the bank, easily walked over; in its second it throws up a spire that can reach a man's shoulder and hangs it with sixty thimbles, all facing the same downhill quarter.

I have drawn this specimen with the spike deliberately incomplete at the crown, because the plant is never finished. Flowering runs from the bottom of the raceme upward at roughly three bells a day, so that the lower fruits are already swelling while the tip is still a knot of grey-green buds. Any plate that shows every flower open is a plate drawn from imagination.

The interior markings are the whole business of the flower. Bumblebees enter head-first along the spotted runway, brush the anthers on the roof of the tube, and back out dusted. The hairs on the lower lip are not decoration but a filter: they exclude smaller insects that would take nectar without paying for it.

A caution, recorded here as elsewhere in this fascicle: every part of the plant is cardioactive and dangerous. It should be drawn, admired, and left standing.

Ferns defeat the ordinary conventions of the botanical plate, which are built for flowers. There is no corolla to open, no fruit to halve, no colour to justify the paint-box. What there is instead is repetition — a single geometric idea stated at three scales in the same organism.

The frond, the pinna and the pinnule are the same shape three times over, each a lance with an enlarged lobe on its upper side. I have drawn only one frond, and drawn it flat, because a whole shuttlecock of them reduces at plate size to a green smudge. The plate should teach the rule, not portray the crowd.

All the plant's reproductive business is on the reverse and requires the lens. Turn a fertile pinnule over in April and it is plain green; by July it carries two neat files of pale sori, each capped by a little umbrella that shrivels and lifts when the spores are ripe.

This species is told from its softer cousin by touch as much as sight: the frond is stiff, glossy, and finely bristled along every margin, so that a hand drawn down it comes away complaining.

No plant in this fascicle changes so fast. The bud hangs for a week, lifts its head in a single morning, sheds two hairy sepals, and unpacks four petals that were folded like a letter. By the third day the petals are on the ground and the flower has become a jug.

I have therefore drawn all three states on one stem, which is a small lie in the service of a larger truth. A plate is not a photograph; it is an argument about what the plant is. Here the argument is that the poppy is a machine for turning a fortnight of colour into a pepper-pot of thirty thousand seeds.

The stigmatic disc rewards the lens. Its rays correspond exactly to the placental walls inside, so the seed-count of a capsule can be estimated from the lid without cutting. I have halved one specimen regardless, for the pleasure of the section.

Every green part bleeds white when cut, and the latex darkens within minutes to a resinous brown. The reader will know the history of that fact and may draw the plant with it in mind.