I grew up calling these daun pandan or pandan leaves. The pandan leaf has a wonderfully, sweet aroma with dashes of freshly cut grass. Used in many Asian cuisines, it is called many names in the various countries it’s found in. You can use it whole to impart a scent and flavour in savoury and sweet dishes, removing it before serving. It can also be pounded with a a little water to produce a dark green, aromatic liquid for flavouring cakes and cookies.
Here in the UK, you can get it fresh online from the many Asian online foodshops or frozen at smaller, local Asian stores.
When using whole and more than 1 at a time, pile them on top of each other and tie a knot in the middle. This will facilitate removal before serving the dish up.
Used in all sorts of rice dishes like Nasi Lemak and Malay Biryanis and Nasi Kunyit (Turmeric Rice).
Pandan leaves are of course also famously used to wrap the chicken in the very popular Thai Chicken in Pandan leaves!