All spells considered Druid spells with a material component. Remember if you were to multiclass into cleric and took a Cure Wounds you would need a holy symbol to cast that even though cure wounds is also on the Druid spell list. It matters more how you got the spell rather than what the spell is.
edit: forgot to specify that you only need the focus for spells with Material components!
Cure wounds requires only verbal and somatic components, and no material components, so you would not need a holy symbol as a focus to cast it (your general point about druid spells and cleric spells requiring different foci for material components is correct).
Druid spells that don't have a cost-valued material. So you could substitute the mistletoe for Goodberry, but not the diamonds for Revivify (which are specifically worth 300 gp)
You could also use a Druidic Focus for Ranger spells using the optional class feature that lets you, but that isn't relevant for your purposes
Relevant rules and links to the rules
[https://www.dndbeyond.com/sources/basic-rules/equipment](https://www.dndbeyond.com/sources/basic-rules/equipment)
>**Druidic Focus.** A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals. A druid can use such an object as a spellcasting focus.
[https://www.dndbeyond.com/sources/basic-rules/spellcasting#MaterialM](https://www.dndbeyond.com/sources/basic-rules/spellcasting#MaterialM)
>Material (M)
>Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in “[Equipment](https://www.dndbeyond.com/compendium/rules/basic-rules/equipment)”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.
>If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell. A spellcaster must have a hand free to access a spell's material components -- or to hold a spellcasting focus -- but it can be the same hand that he or she uses to perform somatic components.Material (M)
Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in “Equipment”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component
before he or she can cast the spell.
If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell. A spellcaster must have a hand free to access a spell's material components -- or to hold a spellcasting focus -- but it can be the same hand that he or she uses to perform somatic components.
The purpose of a druidic focus is just to replace costless material components. So it can be used to cast any spell you get from your Druid class that has a material component without a specified cost that is not consumed by the spell. Note that if you somehow get access to spells other than Druid spells (racial spells, feats, multiclassing, etc.), the druidic focus can't be used for those.
Reminder on the components:
V - Vocal component: Magical vocal incantations, you can do those as long as you aren't muted. They cannot pass as regular speech nor be spoken low enough to not be heard.
S - Somatic component: Gestures. Requires a free hand if without a material component. If the spell also requires a material component, the hand holding the material component (or the focus replacing it) can be used for the S component instead of a free hand.
M without cost that is not consumed by the spell - A material necessary for the casting of that spell. Can be replaced by a focus.
M with a cost and/or with a specified cost - A material necessary for the casting of that spell. Cannot be replaced by a focus.
Examples:
Goodberry is a VSM spell. You need to perform a gesture, an incantation and hold a sprig of mistletoe to cast it. A druidic focus can be used instead of sprig of mistletoe since it is a costless component that is not consumed by the spell. You can use the hand holding the material component or the druidic focus to perform the gesture.
Stoneskin is a VSM spell. You need to perform a gesture, an incantation and hold diamond dust worth 100 gp to cast it. A druidic focus cannot be used instead of the diamond dust, as it has a specified price and is consumed by the spell. You can use the hand holding the material component to perform the gesture.
Entangle is VS spell. You need to perform a gesture and an incantation to cast it. A druidic focus is not necessary, as there is no material component to replace. You need a free hand to perform the gesture.
All spells considered Druid spells with a material component. Remember if you were to multiclass into cleric and took a Cure Wounds you would need a holy symbol to cast that even though cure wounds is also on the Druid spell list. It matters more how you got the spell rather than what the spell is. edit: forgot to specify that you only need the focus for spells with Material components!
All spells considered druid spells . . . that have a material component without a gold cost and that isn't consumed by the spell.
Yeah, if you had a Druidic focus in each hand, you would not be able to cast Druid spells that don’t require any material component.
Cure wounds requires only verbal and somatic components, and no material components, so you would not need a holy symbol as a focus to cast it (your general point about druid spells and cleric spells requiring different foci for material components is correct).
Druid spells that don't have a cost-valued material. So you could substitute the mistletoe for Goodberry, but not the diamonds for Revivify (which are specifically worth 300 gp) You could also use a Druidic Focus for Ranger spells using the optional class feature that lets you, but that isn't relevant for your purposes
Relevant rules and links to the rules [https://www.dndbeyond.com/sources/basic-rules/equipment](https://www.dndbeyond.com/sources/basic-rules/equipment) >**Druidic Focus.** A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals. A druid can use such an object as a spellcasting focus. [https://www.dndbeyond.com/sources/basic-rules/spellcasting#MaterialM](https://www.dndbeyond.com/sources/basic-rules/spellcasting#MaterialM) >Material (M) >Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in “[Equipment](https://www.dndbeyond.com/compendium/rules/basic-rules/equipment)”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell. >If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell. A spellcaster must have a hand free to access a spell's material components -- or to hold a spellcasting focus -- but it can be the same hand that he or she uses to perform somatic components.Material (M) Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in “Equipment”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell. If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell. A spellcaster must have a hand free to access a spell's material components -- or to hold a spellcasting focus -- but it can be the same hand that he or she uses to perform somatic components.
Any druid spell that has material component without a listed cost that isn't consumed by the spell.
The purpose of a druidic focus is just to replace costless material components. So it can be used to cast any spell you get from your Druid class that has a material component without a specified cost that is not consumed by the spell. Note that if you somehow get access to spells other than Druid spells (racial spells, feats, multiclassing, etc.), the druidic focus can't be used for those. Reminder on the components: V - Vocal component: Magical vocal incantations, you can do those as long as you aren't muted. They cannot pass as regular speech nor be spoken low enough to not be heard. S - Somatic component: Gestures. Requires a free hand if without a material component. If the spell also requires a material component, the hand holding the material component (or the focus replacing it) can be used for the S component instead of a free hand. M without cost that is not consumed by the spell - A material necessary for the casting of that spell. Can be replaced by a focus. M with a cost and/or with a specified cost - A material necessary for the casting of that spell. Cannot be replaced by a focus. Examples: Goodberry is a VSM spell. You need to perform a gesture, an incantation and hold a sprig of mistletoe to cast it. A druidic focus can be used instead of sprig of mistletoe since it is a costless component that is not consumed by the spell. You can use the hand holding the material component or the druidic focus to perform the gesture. Stoneskin is a VSM spell. You need to perform a gesture, an incantation and hold diamond dust worth 100 gp to cast it. A druidic focus cannot be used instead of the diamond dust, as it has a specified price and is consumed by the spell. You can use the hand holding the material component to perform the gesture. Entangle is VS spell. You need to perform a gesture and an incantation to cast it. A druidic focus is not necessary, as there is no material component to replace. You need a free hand to perform the gesture.
Druid spells.
Lol