Common Rock-rose

The bright yellow flowers of Common Rock-rose Helianthemum nummularium brighten the hot south-facing hills of the Chilterns throughout the Summer. This beautiful little trailing plant is the larval food plant for several species of butterfly, including Green Hairstreak, Brown Argus and Silver-studded Blue. It also provides an excellent source of nectar for bees and food for several species of small beetles. I have yet to come across one, but pink and white colour variants are occasionally found. Common Rock-rose is a member of the Cistaceae family and as the genus name Helianthemum suggests is sometimes known as the Sun-rose. There are eight sub-species found throughout much of Europe.

Common Rock-rose Helianthemum nummularium, Ivinghoe Beacon, 19/07/2011

Late Summer Butterflies

A gallery of some the Pieridae and Nymphalidae commonly seen flitting across the dry flowery slopes in the Tring area at this time of year.

Green-veined White Pieris napi - female

Gatekeeper Pyronia tithonus - male

Large White Pieris brassicae - female

Marbled White Melanargia galathea

Brimstone Gonepteryx rhamni - female

Meadow Brown Maniola jurtina - male

Speckled Wood Pararge aegeria - male

Small Heath Coenonympha pamphilus - female

Comma Polygonia c-album - female, possibly of the form hutchinsoni

Small White Pieris rapae - male

Purple Emperor

If any proof were needed of the Purple Emperor's unsavoury habits, then here it is! This beautiful male is doing what Purple Emperors like to to best - feeding on a large pile of Dog muck. If you don't have a Dog handy, then Shrimp paste or Banana skins offer a less grisly alternative for attracting these stunning butterflies to the ground. Once they land and begin feeding Emperors can become very docile and can be very easily approached and photographed. Sometimes they will even crawl on to your finger to take salt from your skin, although you might want to wash your hands afterwards!

Purple Emperor Apatura iris - Bernwood (04/07/2009)

Purple Emperor Apatura iris - Bernwood (04/07/2009)

Dwarf Thistle

Anyone who has accidently sat on a Dwarf Thistle Cirsium acaule will know why it is also known as the Picnic Thistle! Lurking in short grazed grasslands on dry calcareous soils, it lies patiently in wait for the unwary picnicker. This low perennial usually has a single stemless purple flower perched on a rosette of spiny leaves, although occasionally 2 or 3 flowers can be found. Dwarf Thistle is common in the Southern half of the country but it becomes rarer as you travel North, with no records at all in Scotland and only a few in Wales. Between June and September these perky little plants help to add colour to the chalky slopes of the Chilterns, along with Selfheal, Rock Rose, Devilsbit Scabious, Thyme and Marjoram.

Dwarf Thistle Cirsium acaule - Ragpits, Buckinghamshire (17/07/2011)

Dwarf Thistle Cirsium acaule - Ragpits, Buckinghamshire (17/07/2011)

Purple Emperor

After mating the elusive female Purple Emperor Apatura iris descends from the tree-tops and searches for a suitable tree for egg-laying. She usually lays her single egg on the upperside of a leaf, in a shady spot near the crown of a Sallow Salix sp. I stumbled across this approachable beauty resting at eye level on a Goat Willow Salix caprea at Bernwood a few years ago, on a boiling hot morning in early July.

Purple Emperor Apatura iris - Bernwood (13/07/2008)

Purple Emperor Apatura iris - Bernwood (13/07/2008)