A garden patch is a fragment of a larger garden. It cannot contain every node the source garden has — that would make it a full garden, not a patch. When a grafted node references a node that exists in the source garden but was not included in the patch, that reference is an upstream node.
The term borrows from version control: the source garden is “upstream” — the origin from which knowledge flows into the patch. An upstream node has known provenance (we know where it is and what it says) but is not present for direct navigation.
Links to upstream nodes are marked with ↑ and are clickable — they navigate to the upstream section of the Node Directory, which documents each upstream node’s name, form type, and brief summary from the source garden. This gives readers enough context to understand the reference without needing access to the source garden.
The ↑ marker distinguishes upstream nodes from ghost links (plain text, not clickable — the node does not exist yet) and from grafted nodes (clickable without a marker — the node is present in the patch).
A garden patch is deliberately selective. Including every referenced node would cascade indefinitely — each included node references more nodes, and so on. The patch boundary is a design decision: graft the nodes needed for the patch to be self-contained and legible, document the rest as upstream references.