Description
                                                                                                            Key Characters:
                                                                            
                                    
                                    
                                                                                                            Growth Form:
                                                                                Plants annual.                                        
                                    
                                                                        
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                            Stems:
                                                                                Stems glabrescent proximally, pubescent distally, becoming glabrous at maturity. Stems erect-ascending to prostrate, branched mostly at base and in proximal 1/2, 0.1–0.5 m.                                                                                
                                                                        
                                                                                                                                                                                    
                                                                                                            Roots: 
                                                                                                                                                                    
                                                                        
                                                                                                            Leaves: 
                                                                                
                                                                                                                        Leaves simple.                                                                                 
                                        
                                                                                                                        Alternate.                                                                                 
                                        
                                                                                                                        Blades ovate, obovate-rhombic to narrowly ovate, sometimes lanceolate, 1.5–3(–4) × 0.5–1.5(–2) cm.                                                                                 
                                        
                                                                                                                        Apex rounded, obtuse, or emarginate, mucronate.                                                                                 
                                        
                                                                                                                        Base cuneate.                                                                                 
                                        
                                                                                                                        
                                        
                                                                                                                        Margins entire to undulate-erose.                                                                                 
                                        
                                                                                                                        
                                        
                                                                                                                        Petioles ± equaling blade.                                                                                 
                                        
                                                                                                                        Stipules absent.                                                                                                                                                            
                                                                        
                                                                                                                                                                                    
                                                                                                                                                                                    
                                                                                                            Flowers:
                                                                                                                        Inflorescences axillary, congested clusters. Bracts of pistillate flowers lanceolate or linear, 1–1.5 mm, 1/2 as long as tepals.                                        
                                                                                Plants monoecious: Pistillate flowers: tepals 5, connate in proximal 1/3 (entirely distinct in all other species), with 3 prominent veins abaxially, spatulate or somewhat clawed, equal or subequal, 2–3 mm, apex rounded or retuse, mucronate; style branches somewhat spreading; stigmas 3. Staminate flowers intermixed with pistillate; tepals (4–)5; stamens 2–3.
                                        
                                                                                                                        
                                                                                                                        
                                                                                                                        
                                                                                                                        
                                                                                                                        
                                                                                                                                                                                                    
                                                                        
                                                                                                            Fruit:
                                                                                                                        Utricles cylindric or narrowly turbinate; 2–2.5 mm; ± equaling tepals; smooth proximally or roughened toward tips; indehiscent or tardily dehiscent.                                        
                                                                                Seeds dark reddish brown to black; lenticular; 0.8–1 mm diam.; shiny.                                                                                                                    
                                                                        
                                                                                                                                                                                    
                                                                                                            Ploidy:
                                                                                                                                                            
                                                                        
                                                                                                            Habitat:
                                                                                                                                                            
                                                                        
                                                                                                                                                                                    
                                                                                                            Elevation Range: