According to observations of naturalists and beekeepers.
Where are you?
SOURCE FOR HONEY BEES:
Minor in most areas
Common buttonbush's distribution extends from southern Nova Scotia, New Brunswick, Quebec, and Ontario south through southern Florida and west through the eastern half of the Great Plains States. Scattered populations exist in New Mexico, Arizona, and the Central Valley of California.
This plant is present in at least 43 states/provinces in this country.
C. occidentalis is a deciduous shrub or small tree that averages 1–3 m (3.3–9.8 ft) in height but can reach 6 m (20 ft). The leaves are opposite or in whorls of three, elliptic to ovate, 7–18 cm (2.8–7.1 in) long and 4–10 cm (1.6–3.9 in) broad, with a smooth edge and a short petiole. The flowers are arranged in a dense spherical inflorescence 2–3.5 cm (0.79–1.38 in) in diameter on a short peduncle. Each flower has a fused white to pale yellow four-lobed corolla forming a long slender tube connecting to the sepals. The stigma protrudes slightly from the corolla. The fruit is a spherical cluster of achenes (nutlets).
Common buttonbush flowers between June and September and produces fruit between September and October.
Prunus fremontii (aka: Desert apricot)
Acer saccharinum (aka: Silver maple, Soft maple)
Cercis orbiculata (aka: California redbud, Western redbud, Arizona redbud, Judas tree, Cercis occidentalis)
Rubus ursinus (aka: California blackberry, California dewberry, California grapeleaf dewberry, Douglasberry, Pacific blackberry)
Rubus spectabilis (aka: Salmonberry)
Salix gooddingii (aka: Goodding's willow, Dudley willow, Valley willow, Western black willow)
Prunus armeniaca (aka: Armenian plum, Ansu apricot, Siberian apricot, Tibetan apricot, Apricot tree)
Prunus andersonii (aka: Desert peach, Desert peachbush, Anderson peachbush, Wild almond)
Pyrus communis (aka: European pear, Common pear)
Salix exigua (aka: Narrowleaf willow, Coyote willow)
Celtis laevigata (aka: Hackberry, Sugarberry, Lowland hackberry, Sugar hackberry, Arizona sugarberry, Netleaf hackberry, Small's hackberry, Southern hackberry, Texas sugarberry)
Acer negundo (aka: Boxelder, Western boxelder, Arizona boxelder, California boxelder, Texas boxelder, Interior boxelder, Violet boxelder)
Aesculus californica (aka: California buckeye, Buckeye, Horsechestnut)
Acer macrophyllum (aka: Bigleaf maple, Big-leaf maple, Oregon maple)
Acer glabrum (aka: Rocky Mountain maple, Douglas maple, Greene's maple, New Mexico maple, Torrey maple)
Salix lucida (aka: Shining willow, Greenleaf willow, Tail-leaf willow, Whiplash willow, Pacific willow, Lance-leaf willow, Longleaf willow, Red willow, Western shining willow)