As requested by Espen204 here's an updated map with Oleander Sage locations if you guys/gals would like any other additions please feel free to send me a message. Happy trails y'all! :
Sage location in Red Dead Redemption 2 | Shacknews
Sage location in Red Dead Redemption 2 | Shacknews
Red Dead Redemption 2 Where to find Oleander Sage
Plants - Red Dead Redemption 2 Walkthrough & Guide - GameFAQs
RDR2 Online - Agarita and Blood Flower nighttime locations Day 2 by Finn Pup
Flora of America | 12 Collectible Cards Locations - Red Dead Redemption 2 - Playthrough Guides
Plants & Herbs Location Guide -
Flora of America | 12 Collectible Cards Locations - Red Dead Redemption 2 - Playthrough Guides