Montana Field Guide

Stems prostrate to ascending, 5–20 cm from a simple caudex. Basal leaves rosulate, ovate to oblanceolate, 1–5 cm long, entire. Stem leaves linear to narrowly oblanceolate. Vestiture of 4- to 6-rayed short-stalked hairs. Petals 6–9 mm long. Fruit globose, 3–5 mm high, style 2.5–4 mm long; seeds 4 to 7 per locule; pedicels curved down, 5–10 mm long. Our plants are variety arenosa (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Great Plains Bladderpod - Physaria arenosa
*Pedicles are recurved downward 5-10 mm long.
*Fruits are globose (not obviously 2-lobed), 3-5 mm high.
*Basal leaves on the outside are oblong to narrowly ovate, not spatulate, and 1-5cm long with entire margins.

Thick-leaf Bladderpod – Physaria pachyphylla, SOC
*Fruiting pedicels curve upwards (ascend), are 3-10 mm long, and less than 2 times longer than fruit.
*Fruits inflated, narrowly elliptic to globose (not obviously appearing 2-lobed), and 3-6 mm tall. Style is 1-3 mm long, shorter than the mature fruit (silicle).
*Basal leaves have distinct petioles and blades. Basal blades are oblanceolate to orbicular in shape, nearly 1 mm thick, and cupped (not folded).
*Plants grow on white to pinkish, limestone and gypsum soils on exposed ridges and slopes in the valley zone.

Sparsely vegetated, sandy soil of grasslands, steppe; plains, valleys (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).