You will need red and green dk (double knitting) cotton - although any yarn will be fine, a 4mm hook, a black button and a brooch pin.
All terminology is UK convention:
Ss: slip stitch
Dc: double crochet
Htr: half treble
Petals: Magic ring or Ch two and work all stitches into the first chain.
Row one: Ch one, ten Dc’s in ring. Pull tight and Ss into first Dc.
Row two: *Ch one, one Dc, Ch one, two Tr in first Dc, three Tr’s in next Dc, two Tr’s Ch one. One Dc in next Dc, Ss in next two Dcs, repeat from * to end working in the Dc's, Ss in first Dc.
Row three: Ch one, one Dc, two Htr in first Dc, three Htr in next Tr, two Htr’s in each of the next five Tr, three Htr in next Tr, two Htr Ch one, one Dc in last Dc of the first petal. (This is the larger petal). Ss in next two stitches, three Dc in next Dc, three Dc’s in next Tr, two Dc’s in each of the next five Tr, three Dc’s in next Tr, three Dc in last Dc of second petal, Ss into next two stitches fasten off. Leave ends to sew on brooch pin.
Row one: Ch nine, Dc in second Ch from hook to last Ch, three Dc in last Ch rotating as you go so you can work on the under side of the Ch, Dc along leaving the last three Ch un-worked, turn;
Row two: Ch one, Dc in each stitch till you get to the middle of the three Dc’s of first row. Work three Dc’s in this stitch, Dc in each stitch leaving the last three stitches un-worked, turn;
Row three: Ch one, Dc in each stitch to middle of three Dc’s, three Dc’s in that stitch, Dc in each stitch leaving last three stitches un-worked, turn;
Row four: Ch one, Dc to the middle stitch of three, Ss into the middle stitch fasten off and sew in starting tail, leave ending tail long enough to sew onto petals If you want a bigger leaf do more chains to start with and repeat rows for the required size.
Sew leaf to petals with larger petal at the bottom. Sew on black button and brooch pin.
Job done x