It has previously been reported that the roots and rhizomes of many species of the genus Cyperus contain quinones. The major quinone (1) of Remirea maritima was accompanied by compounds (2), (3) and (4), and the biosynthesis of (1) from (2) via 2→3→4→1 was postulated, involving formation of a 3-methylfuran by ring closure of a 2-methoxyacetophenone moiety. The rhizomes of Cyperus brevibracteatus yielded two C15 quinones: breviquinone (5, C16H18O4) and hydroxybreviquinone (6, C16H18O5). Breviquinone's UV spectrum was almost identical to (1), and its NMR spectrum showed a 3-methylfuran and an isopentenyl substituent, suggesting structure (5). Reduction of (1) with lithium in liquid ammonia followed by aerial oxidation gave hydroxyquinone (7), which on treatment with diazomethane yielded (5) identical to natural breviquinone. Hydroxybreviquinone (6) was formulated via NMR showing a 3-hydroxymethylfuran grouping. The rhizomes of C. scaber and C. distans yielded four quinones: scabequinone (8), dihydroscabequinone (10), hydroxyscabequinone (11) and scabequinonol (12). Scabequinone (C15H14O4) had UV similar to (1) and (5); its NMR revealed a 3-methylfuran and a 3-isopropylchroman moiety, leading to structure (8). Double resonance experiments verified assignments. Exhaustive ozonolysis of (8) followed by reductive workup gave lactone (9), prepared independently from (-) isopropylsuccinic acid, establishing (8)'s absolute configuration as "R". Scabediol (13) from C. scaber, analogous to (4) in R. maritima, is an attractive biosynthetic precursor of (8) and supports the postulated biosynthesis of (1). Presence of (5) and (8) in botanically related species suggests the biosynthetic precursor of (8)'s 3-isopropylchroman ring is a methoxylisopentenyl moiety. Thus, all type (1) cyperaquinones could derive from preremirol (2), and the described C15 quinones from O-methylpreremirol (14), with twenty-four of twenty-nine new compounds from Cyperus derived from (2). Attempts to effect ring closure of quinol (13) or its quinone (oxidized by DLQ) photochemically were unsuccessful.