Draba nemorosa
 
Yellow Whitlow-Grass

Silique Split Open

Craven
19-May-2020

Note the silique is flattened parallel to the septum.  The silique opens lengthwise and there are multiple seeds in each of the two locules.  Each locule has two rows of seeds but this is hard to make out in this photo. 

Nemorosa: Answers to key questions in Budd's Flora and Manual of Montana Vascular Plants leading to this species. 

plants annual, lacking a branched caudex; NOT [plants biennial or perennial, branched caudex and flower stems from previous years often present]

upper stem glabrous; NOT [upper stem pubescent]

cauline leaves usually 2-5; NOT [flowering stems leafless, or at most with a reduced leaf], NOT [cauline leaves usually numerous, often 10-15]

raceme completely ebracteate; NOT [lowest pedicels subtended by bracts]

flowers yellow; NOT [flowers white]

pedicels 1.5-4 times as long as the silique; NOT [pedicels half as long as the silique]

fruit pubescent; NOT [fruits glabrous]

 

Draba: Answers to key questions in Budd's Flora and Manual of Montana Vascular Plants leading to this genus. 

plants pubescent; NOT [plants glabrous]

plants not with very large basal leaves; NOT [basal leaves 40 cm long or longer]

siliques a few times longer than wide; NOT [siliques many times longer than wide (Boechera)]

siliques flattened parallel to the septum, at least twice as wide as thick; NOT [siliques flattened at right angles to the septum], NOT [siliques round, oval, or 4-angled in cross-section], NOT [pods subglobose]

silique not samara-like; NOT [silique oblong, wing-like, resembling a samara]

silique beakless, often with a short style at the tip <=1 mm long; NOT [silique with a large, usually seedless (sometimes 1-seeded), beak-like, upper portion and a seed-bearing lower portion]

silique rounded to pointed on top or obscurely indented; NOT [silique definitely indented or concave on the top]

silique opening lengthwise; NOT [silique globular, remaining on seed], NOT [silique elongate, breaking in two at the narrowed middle]

silique with >2 seeds in each of the two locules; NOT [silique with 1 to 2 seeds per locule]; NOT [silique 1-seeded]

seeds in 2 rows in each locule (sometimes rows are imperfect); NOT [seeds in 1 row in each locule]

 

Cruciferae: Answers to key questions in Budd's Flora  leading to this family. 

herbs; NOT [shrubs or trees]

plants terrestrial or semiaquatic; NOT [plants aquatic, leaves submerged or floating]

plants not with colored milky juice

plants with more than one normal leaf

some or all leaves alternate; NOT [leaves opposite, whorled, or basal]

leaves without stipules, or having glands; NOT [leaves with stipules]

flowers with two floral rings

calyx regular; NOT [calyx irregular, some sepals smaller than others]

sepals 4

corolla regular in shape; NOT [corolla irregular in shape]

each petal distinct from the others

petals 4

stamens 6, four long and two short

ovary superior; NOT [ovary inferior]

carpels 1 or 2