Our Mystery Plant ("Spiny sow-thistle”, Sonchus asper) is one of them. It’s an annual, growing quickly, getting to be a couple of feet tall, branching toward the top. From the picture you have ...

Unlike the others, such as Dendeocalamus asper cv. ‘Hitam’ and Gigantochloa ... Consult your local extension office to see if the plant is listed as invasive in your area.

Although not as prickly as Sonchus asper, sow thistle does have a more prickly leaf margin ... The shape of the flower head tends to differ as well, and the leaves of young sow thistle plants tend to ...