Xanthium spinosum  ( ) ( ) Asteraceae Stems erect or ascending, branching, 2-10 dm. tall, puberulent; leaves lanceolate, 4-8 cm. long, with a pair of long, narrow lobes on lower half of blade, sometimes with a few small lobes above middle, green above, densely white-pubescent on lower surface, shortly petioled, each with a pair of long, yellow, 3- or 4-parted, stipular spines at base; fruiting bur weakly spiny, tomentose, about 1 cm. long, the beaks inconspicuous. Abundant in waste fields, sometimes along dikes and edges of marshy areas; introduced European weed occasional throughout the United States.  "A Flora of the Marshes of California. Herbert L. Mason".

  Iva hayesiana  ( ) ( ) Asteraceae Herbage glabrate to rough-pubescent, more or less resinous-dotted; stems woody below, not densely leafy, openly branched, the branches ascending from base, to 1 m. tall; leaves spatulate to linear, 3-6 cm. long, narrowed to a short petiole, usually obtuse, heads clustered on short peduncles in a narrow, spike-like, bracteate panicle, the bracts leaflike but reduced; phyllaries distinct, oval to orbicular, 5-10, deciduous in age. Alkaline flats or brackish areas: San Diego County, south to Baja California.  "A Flora of the Marshes of California. Herbert L. Mason".

  Helianthus annuus  (common sunflower) (girasol) Asteraceae Stout annual; stem very hispid and rough, simple or profusely branching, 3-30 dm. tall; leaf blades 7-30 cm. long, usually broadly ovate, serrate, truncate to subcordate, rough-scabrous, green, the petiole often as long as or longer than the blade; heads single and terminal on long, stout peduncles, or the inflorescence forming an open, cymose, long-branched, long-peduncled, leafy-bracted panicle; phyllaries 1.5-2 cm. long, 5-10 mm. wide, broadly ovate, as long as or sometimes longer than the disc flowers, often conspicuously ciliate and densely hispid to hirsute, the apex abruptly narrowed and produced into a long, tail-like acumination; receptacle bracts apically 3-cleft, all 3 cusps acute, the lateral ones somewhat lacerate, the longer, lanceolate middle cusps acute, the lateral ones somewhat lacerate, the longer, lanceolate middle cusp hispid almost to its purple, acuminate, tip, about as long as the disc flowers...

   Pseudognaphalium luteoalbum  ( ) ( ) Gnaphalium luteoalbum Asteraceae Annual, stems 1-3 dm. tall, usually with many sterile, leafy branches from base; herbage white-woolly; leaves oblong-spatulate, auriculate and clasping but scarcely decurrent; inflorescence mainly terminal, usually a dense, globose cluster or the clusters forming a congested or open, corymbose panicle; heads 3-3.5 mm. high; involucre greenish to light brownish, woolly only at base, the phyllaries ovate to oblanceolate or lanceolate, hyaline except for the small, central, herbaceous part, which is pubescent but scarcely glandular, the tips or papillate; pappus bristles hairy below, the hairs interlocking and the bristles tending to cohere at base and to fall in groups. Cultivated in fields and along irrigation ditches; introduced from the Old World. This weedy species has become increasingly common in California in recent years. It is not always easily distinguished from the larger Gnaphalium chilense...

   Erigeron canadensis  ( ) ( ) Asteraceae Erect annual; stems simple below, paniculately branched above, 2-20 dm. tall; herbage hispid with scattered hairs or glabrous, usually dark or bright green; leaves linear to lanceolate, sessile or the lower leaves narrowed to a petiole, entire or toothed, 5-10 cm. long; heads 3-4 mm. high in a dense panicle; phyllaries scarious-margined, nearly glabrous; rays inconspicuous, white, toothed. Common weed in waste places, often abundant on floodlands and along streams. Throughout California at low altitudes; to eastern United States. It is not common in wet habitats, but as a wasteland weed it is to be expected on floodlands.  "A Flora of the Marshes of California. Herbert L. Mason".

   Solanum douglasii  ( ) ( ) Solanaceae Bushy perennial, 0.6-2 m. tall, with angled stems; herbage puberulent to subglabrate. the simple antrorse hairs with heavy, conical bases; leaves ovate, 2-10 cm. long, coarsely sinuate-dentate. acute to short-acuminate, cuneate to subtruncate at base, sparsely puberulent; inflorescence several-flowered, the peduncle 1-3 cm. long, remaining erect at maturity, the pedicels slender, 5-12 mm. long; calyx 2-3 mm/ long at anthesis, the lobes lanceolate-oblong; corolla white with greenish basal spots, the lobes lanceolate-oblong, 6-11 mm. long; anthers 2.6-4 mm. long; style well exserted beyond anthers; seeds light yellow, minutely reticulate-pitted. Streamsides, swales in coastal dunes, drying floodlands, dry slopes, and waste places: coastal North Coast Ranges in Mendocino County, South Coast Ranges from San Mateo County south to southern California; Baja California, east and south through Arizona and New Mexico to northern Mexico....