Petasites japonicus is
a dioecious perennial herb that propagates by extending rhizomes.
Leaves are kidney-shaped orbicular, 15-30cm in width, with bases
deep-heart-shaped, and petioles grow to as long as 60cm in length
and about 1cm in diameter. Before sprouting, scapes rise above the
ground and set flower heads in a corymbs way. The scapes come out
with many bracts with prominent parallel venations. Male plants grow
to 10-25cm tall and set many yellow-white flower heads, while female
ones, at first, are with dense flower heads but grow to
approximately 45cm afterward. Bloom time: March-May. |