Short answer
Night flower is foraged, not bought: 13 Night flower plants are placed around the world, and each gives 2 to 3 per gathering. No trader sells or buys it, and no seed for it is listed. It carries 2 blue runes, which makes it a staple of Reanimation Liquid, Third Eye Salt, Umami, Alkali and Explosive Dust mixes. Flower Bed III, a graveyard decoration, also needs 6.

The Astrologer's Tower
View full-size image ↗Official promotional screenshot · © Lazy Bear Games / tinyBuild · Official media kit · Material credits
Where to find it
wikily.gg places 13 Night flower plants in the world and marks each on its interactive map.
Each gathering yields 2 to 3 flowers. It stacks to 50.
It fits the Alchemist's bag, the Universal bag and the Big universal bag — not the Farmer's bag.
Its runes
One Night flower is 2 blue runes and nothing else, which makes it an easy way to top up blue in a formula.
Our alchemy guide explains how runes add up in the laboratory.
Brews it fits
Reanimation Liquid (2 red, 1 green, 4 blue) — it appears in 45 listed mixes.
Explosive Dust (2 red, 2 blue): Night flower + Red Mushroom works in a two-slot lab.
Umami (4 green, 4 blue): Night flower + Honey + Honey.
Alkali (1 red, 4 green, 2 blue): Night flower + Swamp mushroom + Beeswax.
It also turns up in Third Eye Salt, Berserker Potion III, Zombie Motivator Potion II and III, Spices and Lacquer mixes.
Flower Bed III
Flower Bed III costs 4 Polished Marble, 12 Peat and 6 Night flower, and adds +6 graveyard quality.
It unlocks with Graveyard Decor II. Graveyard quality pays out at every successful sermon, so the flowers come back as bronze.

The graveyard from the official media kit, where Flower Bed III adds quality. No flower beds are shown.
View full-size image ↗Official promotional screenshot · © Lazy Bear Games / tinyBuild · Official media kit · Material credits
Studying it
One Night flower at the Study Table pays +20 blue tech points for 2 Science and 2 Faith. Each item can be studied once.
Sources
- communitywikily.gg — Night flower
- communitywikily.gg — Flower Bed III
- communitywikily.gg — Map
Related pages
Official screenshot · © Lazy Bear Games / tinyBuildAutomationGraveyard Keeper 2 Alchemy Guide
Official screenshot · © Lazy Bear Games / tinyBuildCraftingGraveyard Keeper 2 Reanimation Liquid
Official screenshot · © Lazy Bear Games / tinyBuildCraftingGraveyard Keeper 2 Umami
Official screenshot · © Lazy Bear Games / tinyBuildCraftingGraveyard Keeper 2 Explosive Dust
Official screenshot · © Lazy Bear Games / tinyBuildGuidesGraveyard Keeper 2 Graveyard Layout