Family Guamatelaceae

Guamatelaceae S.H. Oh and D. Potter

~ Rosaceae-Neillieae

Habit and leaf form. Shrubs. Plants non-succulent. Leaves opposite; simple. Lamina entire; cordate- ovate (white-tomentose below); palmately veined; cordate. Leaves stipulate. Stipules intrapetiolar; free of one another; setaceous; persistent.

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes. The ultimate inflorescence unit racemose. Inflorescences terminal; terminal racemes. Flowers bracteate (the bracts filiform); regular; 5 merous; cyclic; tetracyclic. Free hypanthium present (but short - “the petals inserted at the mouth of the calyx tube”).

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; shortly gamosepalous; lobed. Calyx lobes markedly longer than the tube. Calyx regular; imbricate. Corolla 5; polypetalous; red, or pink.

Androecium 10. Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 10; diplostemonous; both alternating with and opposite the corolla members; filantherous. Anthers cordate-ovate; apiculate.

Gynoecium 3 carpelled (but only one component maturing, according to Hutchinson). Carpels reduced in number relative to the perianth. Gynoecium ambigously interpretable, syncarpous (the pistils at first united by the stigmas), or apocarpous; eu-apocarpous, or synstylous (depending on interpretation); superior. Carpel stylate; apically stigmatic. Styles united. Carpel 5–50 ovuled (“several”). Placentation marginal (biseriate on the adaxial suture). Ovary if regarded as syncarpous, plurilocular. Gynoecium stylate. Styles 3; partially joined; apical.

Fruit non-fleshy; an aggregate (sometimes comprising more than one carpel?), or not an aggregate. The fruiting carpel dehiscent; a follicle. Fruit with “numerous” seeds, according to Hutchinson, despite the ovules “several” per carpel. Seeds non-endospermic. Cotyledons 2. Testa smooth (shining, bony).

Geography, cytology. Neotropical. Guatemala, Honduras and Mexico.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Rosales (in Rosaceae). Cronquist’s Subclass Rosidae; Rosales (in Rosaceae). APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Crossosomatales.

Species 1. Genera 1; Guamatela (G. tuerckheimii).

Miscellaneous. This draft description by LW (2009) lacks information on anatomy, anther development and pollen, embryology, and phytochemistry. It also needs pursuing further with reference to features characteristic of Rosaceae.