36 



PUBLIC HEALTH BULLETIN NO. 2 86 



37. Stem finely pubescent; flowers 3-4 mm. long Herpestris, p. 135. 



(fig. 36). 

 37. Stem not finely pubescent; flowers not more Micranthemum, p. 136. 



than 1.5 mm. long (fig. 37), 



Figure 36. 



38. Leaves opposite 39. 



38. Leaves alternate 40. 



39. Flowers solitary in the axils of the leaves; Ludwigia, p. 126. 



leaves less than 3.5 cm. long (fig. 38). 



39. Flowers in stalked head-like spikes; leaves Alternanthera, p. 115. 



over 3.5 cm. long (fig. 39). 



