Answer:

TREES

Answer	Crossword Clue
TREES	Conifers
TREES	Kilmer poem
TREES	Forest

TREES	Joyce Kilmer subject
TREES	Tupelo and Sintoc
TREES	Kilmer opus
TREES	Forest units
TREES	Dendrologist's study
TREES	Things with ramifications
TREES	Kilmer classic
TREES	Long-leaf pines, e.g.

TREES	Places for forts
TREES	Windbreak elements
TREES	Nursery items
TREES	Boulevard liners
TREES	115-Across's poem
TREES	Diagrams of clans
TREES	Logged items
TREES	Inspirers of Joyce Kilmer

TREES	Street enhancers
TREES	Acacia and baobab
TREES	Kilmer poem containing the line "Poems are made by fools like me"
TREES	Nesting sites
TREES	The Lorax claims to speak for them
TREES	Forest obscurers?
TREES	Genealogy charts
TREES	"A nest of robins in her hair" poem

TREES	Aspens and alders
TREES	Dendrologist's concern
TREES	"Poems are made by fools like me" source
TREES	Apples and oranges, maybe
TREES	Ancestry tables
TREES	Street prettifiers
TREES	Shape keepers in a closet
TREES	Cherries, e.g.

TREES	Ancestral diagrams
TREES	Poem with the line "Who intimately lives with rain"
TREES	Windbreak, often
TREES	Ashes, e.g.
TREES	Different ones are hidden in 12 starred answers