Uppercases slot defines.

code/modules/hydroponics/grown/ambrosia.dm

@@ -4,7 +4,7 @@
 	name = "ambrosia branch"
 	desc = "This is a plant."
 	icon_state = "ambrosiavulgaris"
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	filling_color = "#008000"
 	bitesize_mod = 2
 	foodtype = VEGETABLES

code/modules/hydroponics/grown/flowers.dm

@@ -22,7 +22,7 @@
 	name = "poppy"
 	desc = "Long-used as a symbol of rest, peace, and death."
 	icon_state = "poppy"
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	filling_color = "#FF6347"
 	bitesize_mod = 3
 	foodtype = VEGETABLES | GROSS
@@ -86,7 +86,7 @@
 	name = "harebell"
 	desc = "\"I'll sweeten thy sad grave: thou shalt not lack the flower that's like thy face, pale primrose, nor the azured hare-bell, like thy veins; no, nor the leaf of eglantine, whom not to slander, out-sweeten'd not thy breath.\""
 	icon_state = "harebell"
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	filling_color = "#E6E6FA"
 	bitesize_mod = 3
 
@@ -118,7 +118,7 @@
 	righthand_file = 'icons/mob/inhands/weapons/plants_righthand.dmi'
 	damtype = "fire"
 	force = 0
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	throwforce = 0
 	w_class = WEIGHT_CLASS_TINY
 	throw_speed = 1
@@ -149,7 +149,7 @@
 	name = "moonflower"
 	desc = "Store in a location at least 50 yards away from werewolves."
 	icon_state = "moonflower"
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	filling_color = "#E6E6FA"
 	bitesize_mod = 2
 
@@ -176,7 +176,7 @@
 	righthand_file = 'icons/mob/inhands/weapons/plants_righthand.dmi'
 	damtype = "fire"
 	force = 0
-	slot_flags = SLOT_HEAD
+	slot_flags = ITEM_SLOT_HEAD
 	throwforce = 0
 	w_class = WEIGHT_CLASS_TINY
 	throw_speed = 1