Butterfly pose

From a seated position, bring the soles of your feet together, a comfortable distance away from your pelvis.
Fold forward from the hips, allowing your spine to round, placing your hands in front of you.
Relax your legs and spine and allow gravity to work with your body weight.
Hold for 3 to 5 minutes. Eventually this pose can be held up to 20 minutes.
To come out of the pose, use your hands to push the floor away and allow your spine to slowly unroll.
Use your hands to bring your knees towards each other.
Place your arms behind you and lean back to release your hips, and straighten your legs.
Allow your body to settle in this seated position, before moving to a counter pose.

You may want to sit on a folded blanket or a pillow to facilitate the folding forward action.
You could support your knees / thighs with blocks if the sensation is too strong in the thighs or groin.
If this pose is too intense for you, you might want to try a Reclined Butterfly variation.

Try it in class

Stretches the spine, inner thighs and hamstrings.
Increases hip mobility.
Beneficial for menstrual pains.
Stimulates kidneys, ovaries, adrenal and prostate glands.
Stimulates the Urinary Bladder meridian along the spine.
Stimulates the Kidney and Liver meridians if a stretch is felt along the inner thighs.
Stimulates the Gall Bladder meridian if a stretch is felt along the hips.

Adjust the position of your legs to allow your spine to fold forward: you might want to bring your feet closer to your pelvis or even separate your feet a few centimetres apart from each other.
Support your head with your fists or a block in case of neck issues.
Support your chest with a bolster placed across your thighs.
Support your chest and head by placing a bolster on your feet, towards your pelvis and elevate the furthest part of the bolster with blocks.
Place folded blankets or blocks under your knees if the groin or hips are tight.
If you are very comfortable in this pose, a wheat-filled bolster or sandbag could be placed along the spine and/or on the thighs (never on the knees).
Try Butterfly at the wall: lie with your hips against the wall, legs up. Bend the knee, placing the soles of your feet together, allowing your knees to open up to the sides.