Montana Field Guide

Stems ascending, 15–25 cm from a simple caudex. Basal leaves rosulate, erect, linear, 3–7 cm long. Stem leaves similar, reduced upward. Vestiture of 4- to 7-rayed stellate hairs. Petals 6–8 mm long. Fruit globose, 3–4 mm high; style 2–5.5 mm long; seeds 2 to 6 per locule; pedicels curved down, 10–16 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Silver Bladderpod - Physaria ludoviciana, SOC
*Pedicles are recurved downward 10-16 mm long.
*Fruits are globose not 2-lobed, 3-4 mm high
*Basal leaves are erect, linear, 3-7 mm long.

Thick-leaf Bladderpod – Physaria pachyphylla, SOC
*Pedicels curve upwards (ascend), 3-10 mm long.
*Fruits inflated, not 2-lobed, and narrowly elliptic to ovoid, 3-6 mm tall. Style is more than half the length of the fruit (silicle).
*Basal leaves have distinct petioles and blades. Blades are spatulate to oblanceolate in shape, nearly 1 mm thick and cupped (but not folded), and with entire margins [key characteristic].
*Plants grow on pinkish or reddish soils derived from limestone on exposed slopes and ridges in valleys.

Sandy sites on the plains, often around sandstone outcrops.

STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).