Clouded Sulphur Identification Guide
Learn to identify this common pale yellow butterfly and separate it from its close relative, the Orange Sulphur.
Read the full Clouded Sulphur encyclopedia entry →
Key Visual Features
The Clouded Sulphur (Colias philodice) is a medium-sized butterfly with a wingspan of about 1.5 to 2.25 inches.
- Color: Dorsal wings are pale yellow to greenish-yellow; males have a solid black wing border, while females show a broken or spotted black border.
- Pale form females: Some females occur in a whitish "alba" form instead of the typical yellow.
- Markings: A small dark spot on the forewing and an orange spot on the hindwing are usually visible.
- Underside: Yellow-green with a small silver spot ringed in pink or rose on the hindwing, plus scattered small dark spots.
- Resting posture: Almost always perches with wings held closed, rarely basking with wings open.
Where and When You'll See It
Clouded Sulphurs are widespread and common across fields, meadows, clover and alfalfa fields, and roadsides throughout much of North America. They fly low and fast in open sunny areas and are active from spring through fall, with multiple broods produced in most of their range. They are frequently seen nectaring at low flowers alongside their close relative, the Orange Sulphur.
Similar-Looking Species
- Orange Sulphur: Extremely similar and closely related; the Orange Sulphur usually shows more orange suffusion across the wings, especially in males, while the Clouded Sulphur tends to stay a cleaner yellow. The two species commonly hybridize, so some individuals show intermediate coloring that can be difficult to place definitively.
- Cloudless Sulphur: Notably larger and cleaner yellow, without the same black border pattern.
- Alba-form females vs. Cabbage White: Pale alba females can superficially resemble a Cabbage White, but the Clouded Sulphur retains the silver hindwing spot and different overall spot pattern, while Cabbage Whites have rounder wings and simpler black spotting.
Quick ID Checklist
- Medium-sized, pale yellow to greenish-yellow wings
- Solid black border in males, broken/spotted border in females
- Silver spot ringed in pink on the ventral hindwing
- Rests almost always with wings closed
- Common in fields, meadows, and clover/alfalfa habitat
Frequently asked questions
How do I tell a Clouded Sulphur from an Orange Sulphur?
Look at the overall color saturation: Orange Sulphurs usually show more orange wash across the wings, while Clouded Sulphurs tend to stay a cleaner pale yellow, though the two species hybridize and can be hard to separate definitively.
Why don't I ever see this butterfly with its wings open?
Clouded Sulphurs almost always perch with their wings closed, so the underside pattern, including the silver hindwing spot, is usually the best view you'll get while it's resting.
What does the pale form female Clouded Sulphur look like?
Some females occur in a whitish 'alba' form instead of the typical yellow, which can superficially resemble a Cabbage White, though spotting details differ.
Where is the best habitat to find Clouded Sulphurs?
Open fields, meadows, and clover or alfalfa fields are ideal, as these provide both nectar sources and larval host plants.