Marine seaweed Ascophyllum 'nodosum'. Foliage and root growth biostimulant containing auxins and cytokinins. Hydrotech's seaweed extract contains plant hormones called cytokinins and auxins, found regularly in rooting powders and gels. A minimal amount of auxin will trigger root growth. Seaweed extracts provide many beneficial trace elements. Most biostimulant products will have seaweed as an ingredient. Ascophyllum nodosum is the most commonly used seaweed having the most horticultural benefits.