halm vs haulm

halm and haulm both are nouns.

Word	Noun	Adjective	Verb	Adverb
halm	Yes	No	No	No
haulm	Yes	No	No	No

As nouns, halm and haulm are synonyms defined as:

halm and haulm: stems of beans and peas and potatoes and grasses collectively as used for thatching and bedding

halm (noun)	haulm (noun)
stems of beans and peas and potatoes and grasses collectively as used for thatching and bedding	stems of beans and peas and potatoes and grasses collectively as used for thatching and bedding