Description
                                                                                                            Key Characters:
                                                                            
                                    
                                    
                                                                                                            Growth Form:
                                                                                Annual herbs.                                        
                                    
                                                                        
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                            Stems:
                                                                                Stems ascending to erect, 10–45 cm long, inconspicuously pubescent at least toward base.                                                                                
                                                                        
                                                                                                                                                                                    
                                                                                                            Roots: 
                                                                                                                                                                    
                                                                        
                                                                                                            Leaves: 
                                                                                
                                                                                                                        Leaves simple.                                                                                 
                                        
                                                                                                                        Alternate.                                                                                 
                                        
                                                                                                                        Blades linear to linear–spatulate, 5–9 mm long, 0.6–1.8(–2) mm wide.                                                                                 
                                        
                                                                                                                        Apex acuminate or sometimes acute.                                                                                 
                                        
                                                                                                                        
                                        
                                                                                                                        Surfaces glabrous.                                                                                 
                                        
                                                                                                                        Margins revolute and minutely serrulate.                                                                                 
                                        
                                                                                                                        
                                        
                                                                                                                        Sessile.                                                                                 
                                        
                                                                                                                                                                                                    
                                                                        
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                            Flowers:
                                                                                                                        Flowers in helicoid cymes.                                        
                                                                                Flowers bisexual (perfect), actinomorphic.
                                        
                                                                                Sepals narrowly ovate to lanceolate, 3–4 mm long, margins glandular ciliate, apex long–acuminate.
                                        
                                                                                Petals pale yellow, obovate, 4–5(–6) mm long, apex with a small median tooth, distinct.
                                        
                                                                                Stamens connate at base; anthers dithecal, opening by longitudinal slits.
                                        
                                                                                                                        
                                                                                Ovary superior, flowers homostylous; ovary superior, placentation axile; ovules 2 per carpel, pendulous, anatropous; stigmas terminal and linear-clavate.                                        
                                                                                                                                                                                                    
                                                                        
                                                                                                            Fruit:
                                                                                                                        Capsules depressed–globose; 1.8–2.1 mm long; with an apical beak ca. 0.2–0.3 mm long.                                        
                                                                                Seeds flat.                                                                                                                    
                                                                        
                                                                                                                                                                                    
                                                                                                            Ploidy:
                                                                                                                        2n = 20
                                                                            
                                                                        
                                                                                                            Habitat:
                                                                                                                        naturalized on dry ridges; ʻOhikilolo Ridge and Mokuleʻia Valley; Waiʻanae Mountains; Oʻahu.
                                                                                                                    
                                                                        
                                                                                                                                                                                    
                                                                                                            Elevation Range:
                                                                                                                        300–600 m.