Wayne's Word Index Noteworthy Plants Trivia Lemnaceae Biology 101 Botany Scenic Wildflowers Trains Spiders & Insects Search Unusual Malva pseudolavatera? ("Malva X") From San Marcos ADDENDUM (19 July 2019)        Unusual Weed That Took Over Field       Back To Malva X Page   Field Where Malva X Was Discovered: No Trace Of Malva X, But Entire Field Covered With Naturalized Weed Positively Identified As Stinkwort (Dittrichia graveolens--Asteraceae) Identified as stinkwort (Dittrichia graveolens), a fall-blooming, naturalized weed in the sunflower family (Asteraceae) native to Europe, Mediterranean, southwest Asia and Africa. I confirmed ID when it flowered in September. This species is considered to be a serious, aggressive weed in San Diego County and especially in California wine country. The stems and leaves are covered with minute, globose, sessile, sticky resin glands and dense hairs that provide insulation against dehydration and allow the plant to survive the heat & drought months of summer & fall. Reported to cause allergic contact dermatitis in some people. Allelopathic effects on other weeds & cultivated crop plants has also been reported. Stinkwort (Dittrichia graveolens) in full bloom (24 September 2019). It belongs to the family Asteraceae, tribe Inuleae along with arrowweed (Pluchea), everlasting (Gnaphalium), nest-straw (Stylocline), and cudweed (Filago). Species in this tribe have distinctive anthers that are tailed at base. Return To WAYNE'S WORD Home Page Return To NOTEWORTHY PLANTS Page Go To Biology GEE WHIZ TRIVIA Page Go To The LEMNACEAE ON-LINE Page All text material & images on these pages copyright © W.P. Armstrong