Pineapple Weed;  Chamomilla suaveolens

Mid bloomer.  Small yellow-green pineapple-shaped flower heads, distinctive odor, low plant.

Notes:  Aster (Sunflower) family, Mayweed Tribe.  Can have people gently squeeze flower to see what it smells like.  Also called Wild Chamomile.  It is related to feverfew, used for migraines.  Chamomile is used for arthritis, some species used to make chamomile tea for relaxation.

Some sources give the Pineapple Weed as Matricaria mactricarioides, e.g., Peterson & Niehuas.  The USDA lists nothing for Chamomilla and 4 species for Matricaria, but nothing for Matricaria mactricarioides.  The classification below is for genus Matricaria.  

Click on genus name below to go to USDA for this genus

Kingdom Plantae -- Plants 
    Subkingdom Tracheobionta -- Vascular plants 
        Superdivision Spermatophyta -- Seed plants 
            Division Magnoliophyta -- Flowering plants 
                Class Magnoliopsida -- Dicotyledons 
                    Subclass Asteridae 
                        Order Asterales 
                            Family Asteraceae -- Aster family 
                                Genus Matricaria L.. -- mayweed

Contains 4 Species and 4 accepted taxa overall

Down one level 

Species Matricaria courrantiana DC. -- crown mayweed
Species Matricaria discoidea DC. -- disc mayweed
Species Matricaria occidentalis Greene -- valley mayweed
Species Matricaria recutita L. -- German chamomile

Pineapple Weed;  Chamomilla suaveolens