Like all the 11 US species of this genus, linaria dalmatica
is a non-native plant, originating in Europe, and now widespread across the western half of the US, as is the similar, equally common linaria vulgaris
. The main difference is the leaf shape; broad and ovate for the former, narrow and linear for the latter.
All plant parts are hairless. Stems are tall, up to 4 feet, and branched, bearing greyish-green, clasping leaves at closely-spaced intervals. Leaf tips taper smoothly to a point. Flowers are borne on stalks of up to half an inch, and they are formed of a green, lobed calyx, half an inch long, and a yellow corolla up to 2 inches long. This has two lips; the upper has two lobes, and forms a hood, while the the slightly longer lower lip has three lobes, and extends backwards to form a narrow spur. The four stamens (in two different-length pairs) are not exserted.
Most US specimens of linaria dalmatica are ssp dalmatica
; the much less common ssp macedonica
is characterized by ovate calyx lobes less than 0.1 inches long; the former has lanceolate calyx lobes more than 0.1 inches long.