Polygala alba (White Milkwort) - photos and description
General: Plants decumbent to erect, usually with several stems from the caudex. Stems simple. Plants glabrous.
Flowers: Flowers are white and grow in terminal spikes, we measured a spike at 6 cm long, and a flower at 4 mm long.
Leaves: Leaves are cauline, alternate, linear; we measured a leaf at 4 cm long and 2 mm wide.
Height: Height listed in Budd's Flora to 40 cm, we measured plants to 27 cm tall.
Habitat: Dry grassland in southeast Saskatchewan.
Abundance: Rare, ranked as an S3 (as of 2021) by the Saskatchewan Conservation Data Centre.
Origin: Native.
Similar species: This plant might be mistaken for Polygala senega which has a similar growth habit and inflorescence. However that plant has lanceolate leaves, whereas Polygala alba has linear leaves. Budd's Flora and Taxonomic Reminder for Recognizing Saskatchewan Plants also both list as a distinguishing characteristic the shape of the inflorescence - oblong for P. senega, cylindrical for P. alba. I haven't found this helpful because I've seen oblong spikes on both plant species.
When and where photographed: Photos taken June 19th, 20th, and July 21st in the Souris River valley, about 200 km southeast of our home in Regina, SK.