Signaling peptide (root growth factor) that promotes root hairs formation and growth (PubMed:23370719). Regulates the pattern of root growth and lateral root development by modulating the length and the number of cortical cells in the root apical meristem (RAM), and the anticlinal asymmetric cell divisions in lateral root initiation cells (By similarity). Binds to LRR receptor-like serine/threonine-protein kinases to trigger their dimerization with SERK proteins and subsequent signaling. Expressed in the root portion above the meristem, in sepals and pollen grains, and in cotyledons and leaves lamina, stipules and petioles. In primary roots and mature lateral roots (LRs), expressed in cortex and epidermis from the border of the maturation zone up to the colet (PubMed:23370719). Restricted to the nonhair cell files in the epidermis, but present in all cortical cells regardless of their position (PubMed:23370719). Induced during lateral root formation in mature lateral roots (PubMed:23370719). Patchy expression in cotyledons and leaves, but accumulates at the base of the cotyledon petioles and in stipules (PubMed:23370719). In flowers, irregular repartition in the sepals and pollen grains (PubMed:23370719). The tyrosine sulfation is critical for the function of the peptide. Shorter and fewer root hairs. 'Golven' means irregular waves in Dutch. Belongs to the RGF family.