Monographs Details: Mezia
Authority: Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.
Description:Genus Description - Woody vines or hanas. Leaves opposite, the petiole eglandular, the lamina bearing impressed glands or eglandular, the stipules minute, interpetiolar, caducous. Inflorescence tightly reddish- or dark brown-sericeous throughout, axillary and terminal, decompound, containing much-reduced bract-like leaves below the floriferous bracts, the flowers ultimately borne in umbels of 4; bracts smaller than the bracteoles, abaxially sericeous, adaxially glabrous or sparsely sericeous near the margin, eglandular, deciduous before maturation of the fruit; peduncle well developed; bracteoles borne just below the flower, large, globose cymbiform, the inner enclosing the bud until anthesis, the outer enclosing both bud and inner bracteole, abaxially sericeous, adaxially glabrous or sparsely sericeous, often splitting at the apex at anthesis, persistent or deciduous; pedicel very short, to 2 mm long in fruit; old flowers (not setting seed) deciduous at base of peduncle, not at joint between peduncle and pedicel. Sepals free, narrowly oblong or spatulate, rounded at the apex, abaxially tomentose, adaxially glabrous or bearing a few hairs, the anterior sepal eglandular, the 4 lateral sepals each bearing 2 large compressed glands, these distinct or partially to completely connate. Petals yolk-yellow, plane or slightly concave, the lateral 4 reflexed, the posterior erect or reflexed in the limb. Receptacle glabrous. Stamens 10, the filaments basally to 1/2 or more connate, the 2 opposite the postero-lateral petals longer and thicker than all others; anthers dimorphic, the 5 opposite the sepals differing in size and shape of the connective, and sometimes in pubescence, from the 5 opposite the petals. Ovary of 3 carpels, adaxially adnate to a common axis, 1 anterior and 2 posterior, all fertile, sericeous; styles 3, subterminal, the apex with a large internal stigma and dorsally truncate or short-hooked or pedaliform, the anterior style shorter and often slenderer than the 2 posterior styles. Fruit schizocarpic, comprising 3 (or less by abortion) 1-seeded samaras borne on a pyramidal torus, each samara bearing 2 large lateral wings free or more often continuous at the base, a smaller dorsal wing, and often additional crests or winglets between them or outside the lateral wings.
Discussion:17. Mezia Schwacke ex Niedenzu, Nat. Pflanzenfam. 3(4): 58. 1890.
Stenocalyx Turczaninow, Bull. Soc. Nat. Mosc. 31(1): 393. 1858, non Stenocalyx Berg, 1854, Myrtaceae.
Diplopterys Adr. Jussieu sect Mezia (Schwacke ex Niedenzu) Niedenzu, Arb. Bot. Inst. Lye. Braunsberg 4: 16. 1912.
Type. Mezia araujei Schwacke ex Niedenzu.
This is a mascagnioid genus, distinguished by its four-flowered umbels, the reddish or dark brown sericeousness of the inflorescence, the very large bracteoles that completely enclose the flower until anthesis, the very short (practically absent) pedicel, the long narrow sepals four of which bear large compressed or rarely connate glands, and the dimorphic anthers. It is also most unusual in this family for abscission of old flowers to be at the base of the peduncle instead of between peduncle and pedicel. The genus most like Mezia is Jubelina, which resembles Mezia in having umbels, large bracteoles, long narrow sepals, compressed or connate calyx glands, and large mascagnioid fruits. However, Jubelina has a well developed pedicel, the bracteoles do not enclose the bud, abscission of its flowers is at the peduncle-pedicel joint, and its samara has sterile cavities on each side of the fertile locule, which are not present in Mezia.
Mezia comprises several species in addition to the ones treated here, these occurring mostly in Brazil, as far south as Rio de Janeiro.