The Collaborative International Dictionary
Haplostemonous
Haplostemonous \Hap`lo*stem"o*nous\ (h[a^]p`l[-o]*st[e^]m"[-o]*n[u^]s), a. [Gr. "aplo`os simple + sth`mwn a thread.] (Bot.) Having but one series of stamens, and that equal in number to the proper number of petals; isostemonous.
Wiktionary
haplostemonous
a. (context botany English) Having a single series of stamens, equal in number to the proper number of petals and alternating with them.