When expanding spell knowledge, it can be frustrating to come across unknown ingredients, particularly in old grimoires and texts that require herbs that are difficult to grow or buy in the southern hemisphere. Over the weekend for example, I was looking over positive health spells, and repeatedly encountered angelica root, which I had no hope of finding on a Sunday in a quiet town. This and many other magical plants originated in the far north, and grows wild in countries such as Russia and Finland. As such, unless we buy in dried or powered root in preparation for spells (and believe me, I have plenty of jars of such ingredients as well), we have to either delay the ritual or substitute the ingredient.
Being open to intuiting ingredients for spells is a large factor in eclectic witchcraft and nature magick, among other forms of ritual spellcasting. Gathering ingredients for a spell or ritual is a mindfulness exercise in itself, as we meditate on our intentions while collecting each required representation of the spell's focus. In doing so, rather than just opening a cupboard and measuring out ingredients, we will spend more time subconsciously considering what we want to achieve, and in doing so, will be focused more intently when the time comes to perform the spell or ritual. When doing this, I find it auspicious to encounter the perfect substituted ingredient in nature, and my becomes more positive about my impending success.
Angelica root is also known as wild celery, and it's one of several sweetly scented edible roots. Its name etymology comes from a Greek word for archangel, and it has a musky aroma. It is also used as a flavouring in liqueurs such as vermouth and in gin distillation.
When deciding what ingredients to substitute, consider first its reason for existing in the spell. Is it symbolic of its colour, its connection to the earth, or for its ingestible qualities? Consider which factor is most important to your intended outcome, and substitute in the most meaningful way you can with what you have around you. Allow yourself to become creatively inspired when solving these problems. Light a focusing intentions spell candle (or ritually dress and charge one for this purpose) to inspire you for the spell preparation and not just the casting itself, and consider the factors you are substituting before you set out to discover the new ingredient you'll use.