Using kalpasi (which is also known as Black Stone Flower) in a biriyani?

Kalpasi is type of lichen, usually used in spices for typical Chettinad and West Indian (Maharashtrian) Cuisines.

Dry ground kalpasi has little or no smell and should be roasted in little oil to get its actual and full aroma.

It has a distinct smell, which it would impart, if used properly i.e. after roasting (also depends on how and for how much time you marinate).

Its generally used in combination with other spices like cardamom, cloves, bay leaves, cinnamon, nutmeg, star anise, saffron, peppers etc. for flavor.

On its own, it can't add much flavor.

Kal Pasi or Dagad ka Phool or Patthar ka phool / Black Stone Flower / Kalu Pacchi / Ratthi pavalu / Kallu houvu also known as Parmotrema perlatum is a particular variety of lichen ( fungus in a symbiotic relationship with algae or cyanobacteria - per Wiki). Used extensively in Andhra / Kannada / Mahashtrian Godu Goda masala / Tamil -Chettinad cooking.

It is available in the USA in South Indian grocery stores. It looks like blackish-brown dried paint flakes - has no smell ( well, hardly any - ) or taste, when raw. Unfortunately, it cannot be easily powdered, since it has the consistency of a thin paper confetti.

You either roast it in oil / tadka, with cinnamon sticks or bay leaf etc. and use it in the cooking OR you can put it in a cloth (tea?) bag and leach it into the curry. I prefer the former - the oil saute-ing method. It gives the final cooked dish product a pleasant earthy taste and an indescribable freshness to it.

It costs about 5 USD for 50 grams, which will last you 10 years. Since it is a lichen, which is scraped off of bark of trees and stones, you will want to clean it, especially the portion that you are going to tbe cooking with. Remove all bits of dirt, and bark pieces and extraneous roots.

I just started cooking with it - and I used it very extensively both for veg and nonveg cooking - and my results have been nothing short of miraculous - and I would give it 5 stars. I wish I had known about this earlier...

Dagadful (Kalpaasi) is a beautiful aromatic spice in western and south indian cooking, however many people don't know much about it. While making your Goda masala (for Maharashtrian) or Curry masala (for south indian) if you use Dagadful, it gives you beautiful but little strong smell. I can definitely advice you to use this as I am in masala making business for last 7 years.