Gnomish
hum(i)los
noun. (red) poppy
humloth
noun. (red) poppy
humethla
noun. (red) poppy
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun appearing as G. humilos or humlos “poppy” in the Gnomish Lexicon of the 1910s, apparently a combination of G. hûm “sleep” and G. lôs (GL/49); compare to ᴱQ. fúmelot, its likely Early Qenya cognate (QL/39). It was followed by an archaic form †humethla, probably cognate to the other Early Qenya “poppy” word: ᴱQ. fumella (GL/49; QL/39). In other notes in the period, Tolkien had G. humethla and humloth as cognates to ᴱQ. fumella, which Tolkien described as “the red poppy that grew in hosts in Lorien’s gardens” (PE15/14).
Neo-Sindarin: For purposes of Neo-Sindarin, I would update this word to ᴺS. lurloth “poppy, (lit.) flower of sleep” using the element [ᴺS.] lûr “sleep” which is better supported by Tolkien’s later writings, and S. loth “flower” as the final element.