To clarify the effects of peripheral herbal plants on Glehnia littoralis growth in coastal sand dunes, the morphology of their aboveground portions was surveyed in five communities: Carex kobomugi, Calystegia soldanella, Ischaemum anthephoroides, Oenothera biennis, and Elymus mollis. Correlation coefficients (CC) were generally significant at the 1% level between community properties [total aboveground biomass (B) and height (H) of dominant species per unit area] and those of G. littoralis [leaf number (NI), petiole angle (Anp), petiole length (Lp), petiole weight (Wp), Lp/Wp, Lp/weight of leaf blade (Wb), Wp/total weight (Wt), specific leaf area (SLA), stem length (Ls), and Ls/weight of stem (Ws)] The exceptions were among four pairings: B and NI, B and Wt, H and NI, and H and Wt. Of the two community properties, biomass had the greatest association with leaf properties while H was most closely related to those of the stems. Petiole angle increased along with leaf order, from $0^{circ};to;42^{circ}$ for the C. kobomugi community, from $5^{circ};to;55^{circ}$ for Calystegia soldanella, from $49^{circ};to;74^{circ}$ for I. anthephoroides, from $54^{circ};to;80^{circ}$ for O. biennis, and from $75^{circ};to;85^{circ}$ for E. mollis. In all communities, the properties of Wp, SLA, and Wb increased up to the third or fourth leaf, but then decreased; the exception was for Lp/Wp, which was the reverse. Leaf order of the largest one moved from first position to third as either B or H increased in a community.