Bilvashtakam, a verse glorifying the results of offering Bilva leaves to Lord Shiva, mentions 7 other leaves, which are equivalent to Bilva. Thse are called together as asta bilvas.
As per the below sloka, 8 different kinds of leaves are revered as Vilvas or glorified as Vilva(s):
Thulasi Bilva Nirgundee Apaamarga Kapihtagou
Shamee Cha Aamalakam Dhoorva Asta Bilva Prakeerthitha:
Shamee Cha Aamalakam Dhoorva Asta Bilva Prakeerthitha:
Thulasi (Tulasi, Thuzai) - Ocimum Sanctum
Bilva (Vilvam) - Cynodon Dactylon
Nirgundi (Nochi) - Vitex negundo
ApaaMaarga (Nayuruvi) - Achyranthes aspera
Kabitha (Vilam) - Limonia acidissima
Shamee (Vanni)-Prosopis Spicigera
Aamalakam - (Malai Nelli) - Phyllanthus Emblica
Doorva - (Aruham pul) - Cynodon Dactylon
Needless to say, each of these leaves have unique medicinal qualities and also some of them have falvors. Some of them like Thulasi are consumed directly, while others are powdered and used in various Ayurvedic perparations. Thus offering these medicnal leaves to God, in in our glorious tradition, which also makes them readily reachable when in need of them for certain disease curitng etc..
Bilva,Thulasi & Nochi hav good fragrance. Thulasi and Noci are usedin the cure of cold, fever etc.. Our siptures, thus give us, unvaluable treasures, in the form of slokas, etc.. Let's enjoy our lives with those.