arnoldparrot's Identifications

Common Sow-thistle (Sonchus oleraceus) Introduced/naturalized, common, annual plant in the Cichorieae tribe and Asteraceae family that is native to Europe and Western Asia. Botanical characteristics: Stem is erect, hollow with milky sap, and proximally branched. It grows 10–120 cm (4 - 47 inches) tall, prefers full sun and can tolerate most soil conditions. Leaves are highly variable in shape, usually finely toothed and sometimes lobed but almost always clasping the stem. Common pollinators on the yellow flowers include bees and flies. Fruit is flat, 2.5--3.8 mm long, 2--4-ribbed, cross-wrinkled, and dark brown, with pappus bristles +- 2 × length of fruit. It spreads its many seeds via wind or water. A.k.a. Smooth sow thistle, Annual sow thistle, Hare's colwort, Hare's thistle, Milky tassel, Milk thistle, and soft thistle. The common name 'sow thistle' refers to its attractiveness to pigs, and the similarity of the leaf to younger thistle plants.

"Common. After the flowers are fertilized, they close again into an onion-dome shape that is distinctive. The shape of the leaves is extremely variable. Cauline leaves are clasping, the lower ones with clasping lobes with tips that are acute, but not curved or coiled. This is unlike the rounded and strongly curved or coiled tips of the clasping lobes in Prickly Sow-thistle (Sonchus asper). The terminal lobe of the cauline leaves is often widely arrow-shaped. Fruits have 2–4 ribs and are cross-wrinkled. The plant can grow very tall (as much as 6–8 feet), although 2–3 feet is more usual."
Monterey County Wildflowers https://montereywildflowers.com/asteraceae-dandelion-2/

Jepson eFlora https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=5118

Plants of Monterey County: an Illustrated Field Key, 2nd edition, Matthews and Mitchell, 2015, pp. 54-55.

Flora of Fort Ord: Monterey County, California, David Styer, 2019, p. 59.

Monterey County Wildflowers: a Field Guide, Yeager and Mitchell, 2016, p. 321.