The Helianthus decapetalus, apparently a variety, with eight petals.

August 29.
Heavy rain in the night and this forenoon. 

P. M. — To J. Farmer's by river. 

The Helianthus decapetalus, apparently a variety, with eight petals, about three feet high, leaves petioled, but not wing-petioled, and broader-leaved than that of August 12th, quite ovate with a tapering point, with ciliate petioles, thin but quite rough beneath and above, stem purple and smoothish, Hosmer's bank, opposite Azalea Swamp. 

Fragrant everlasting in prime and very abundant, whitening Carter's pasture. 

Ribwort still. 

An apparent white vervain with bluish flowers, as blue as bluets even or more so, roadside beyond Farmer's barn.

H. D. Thoreau, Journal, August 29, 1856

Helianthus . . . broader-leaved than that of August 12th . . . See August 12, 1856 ("Am surprised to see still a third species or variety of helianthus. . . I cannot identify it."); see also August 11, 1856 ("A new sunflower at Wheeler's Bank, this side Corner Spring, which I will call the tall rough sunflower; . . . It does not correspond exactly to any described.”);  August 11, 1858 (“See a small variety of helianthus growing with the divaricatus, on the north side of Peter’s path, two rods east of bars southeast of his house. It is an imperfect flower, but apparently answers best to the H. tracheliifolius.”)

Fragrant everlasting in prime and very abundant . . . See August 10, 1856 ("Fragrant everlasting, maybe some days.”); August 11, 1858 (“I smell the fragrant everlasting concealed in the higher grass and weeds there, some distance off.”)

White vervain with bluish flowers . . . See August 6, 1853 ("lower leaves of some catnip and a white vervain have turned. ")