Linaria vulgaris
 
Yellow Toad-Flax

Lower Lip, Inner Face

Hudson Bay Trout Pond, 1.5 Miles East of Hudson Bay
01-August-2021

The corolla is composed of a three-lobed lower lip and a two-lobed upper lip.  The upper lip has been removed  from this specimen (a flower bud).  Note the four fertile (anther bearing) stamens.  Two of the stamens are longer than the other two, an arrangement known as didynamous.

Vulgaris: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 
plants perennial with extensive rootstocks; NOT [plants annual]
cauline leaves linear to linear-lanceolate; NOT [cauline leaves ovate to lanceolate]
cauline leaves narrowed to a petiole-like base; NOT [cauline leaves clasping at base]
flowers 2-3 cm long; NOT [flowers 3-4 cm long]
flowers yellow and orange; NOT [flowers white, pink or purple]

 

Linaria: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. 
leaves not all basal
flowers in terminal racemes; NOT [flowers axillary]
corolla spurred at the base
only two or four stamens anther-bearing, others sterile or absent; NOT [five anther bearing stamens]

 

Scrophulariaceae: Answers to key questions in Budd's Flora  leading to this family. 
herbs; NOT [shrubs or trees]
plants green or with some chlorophyll; NOT [plants parasitic or saprophytic, without chlorophyll]
plants not aquatic
stems not square
leaves not bearing bladders
flowers not in heads or spikes; NOT [flowers in long or short spikes], NOT [flowers in heads or in form resembling a head]
flowers with two floral rings
petals wholly or partly united forming a tube or bell
corolla irregular; NOT [corolla regular]
ovary superior; NOT [ovary inferior]
fruit a many-seeded capsule; NOT [fruit with 4 nutlets]