Brook'weed` noun (Botany) A small white-flowered herb ( Samolus Valerandi ) found usually in wet places; water pimpernel. Found on http://www.encyclo.co.uk/webster/B/104
Brookweed (Samolus Valerandi) is a small, almost cosmopolitan herbaceous plant belonging to the Primulaceae. It abounds in marshes near the sea and bears small white flowers in racemes on a slender stem springing from the centre of a rosette of bright green leaves. Found on http://www.probertencyclopaedia.com/browse/BBA.HTM