Thalia

Erect, perennial marsh plants with a basal rosette of leaves and an often very elaborate synflorescence. Leaves ovate-lanceolate, rounded or subcordate at base. Inflorescence paniculate, with slender branches; bracts subtending flower pairs boat-shaped, deciduous; bracteoles absent. Calyx of 3 very small, similar, hyaline sepals. Petals free but adnate to staminal tube for a very short distance, membranous. Androecium: outer staminode 1, petaloid, showy; hood-shaped staminode with 2 appendages near middle of lobe, both pointing down into staminal tube; callose staminode firm and fleshy with a petaloid margin; fertile stamen with a petaloid appendage. Ovary 1-locular, with a single ovule; style helically twisted when triggered, with a very long, lip-like protrusion from ventral rim of stigmatic orifice. Fruit caryopsis-like, with very thin pericarp. Seed with a small 2-lobed aril; perisperm canal branched from base.