Rhigospira quadrangularis, portion of a plant. 1) the inflorescence and 2) a flower, to scale; 3) corolla in bud, showing the pyramidal form of the erect segments in aestivation and 4) the same cut open when expanded, showing their simple sinistrorse convolution and the nearly basal position of the stamens, both magnified; 5) the calyx, disk, very short style, clavuncle, and stigmata, to scale; 6) the same, magnified; 7) a stamen, much magnified.