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its potential to also invade and become widely dispersed in the U.S. Narrow- leaved Dalmatian toadflax currently infests several azeas in western Oregon, northwestern Washington, British Columbia, and possibly in Colorado. Yellow toadflax is native to south-central Eurasia where it was used for fabric dyes and for medicinal purposes. It was imported into North America in the late 1600s as an ornamental and for folk remedies. 1t was widely distributed in North America by the mid 20'" century. Unfortunately in states where yellow toadflax is not noxious, it still is sold by some nurseries as "butter and eggs" or as "wild snapdragons:' Seeds of yellow toadflax germinate and emerge in early to mid-May while Dalmatian toadflax seeds may germinate and emerge earlier especially on south or southeast facing slopes. Dalmatian toadflax typically flowers begining in late May or June in Colorado and may continue until fall, particularly rf moisture is not limiting. Yellow toadflax begins to /lower when shoots are from 16 to 24 inches tall, mid- to tale May along the Front Range in Colorado, although at higher elevations (9,000 feet or more), flowering may not begin until late July. BIOLOGY Germination and Emergence Seeds of yellow toadflax germinate and emerge in early to mid-May while Dalmatian toadflax seeds may germinate and emerge earlier especially on south or southeast facing slopes. In Washington, Dalmatian toadflax seedlings on south facing slopes usually emerge in early to mid- March. First year Dalmatian toadflax plants often produce prostrate shoots in fall that survive into the following spring. Mature Dalmatian toadflax may produce prostrate shoots, but to a lesser extent, and these typically die before winter and shoots emerge the following spring from roots. Yellow and Dalmatian toadflax shoots that grow from roots emerge as early as mid-March along the Front Range in Colorado, but vegetative shoot emergence may not begin until mid- to late June at 9,000 feet to 10,000 feet. In Canada, vegetative shoots begin to emerge when soil temperatures range from 42 to 50 F. Root growth Seedling root develop is slow and represents a life stage vulnerable to control attempts and plant competition. Disturbance promotes toadflax invasion and may be necessary for establishment to occur. However once established, toadflaxes readily spread into adjacent non- disturbed azeas. Much of this spread is by vegetative means, reflecting a vigorously-growing root system. Dalmatian toadflax roots may grow 20 inches deep or more nine weeks after seedlings have emergedand 3 ,~ ~~ Figure 2: DALMATION TOADFlA7C [Linaria dalmatica (L.) Mill. =Linaria genistifolia ssp. dalmatica (L.) Maire & Petitmengin]. Noxious. This diNers from yellow toadflax principally in being larger and having differently shapetl leaves. Clumps of stems are 3 to 4 feet tall. Waxy leaves are broad, ovate, sometimes heart shaped and upper leaves clasp the stem (an important difference). Seeds are irregular in shape, angular, somewhat flattened, thin-edged, strongly netted, tan-gray and 1/24 to 1/16 inch across. It is not as common, but is more aggressive than yellow toadflax. It is reported in various parts of the state from 5,000 [0 6,500 feet.