1 Cauline leaves expanded at the
base , usually
auriculate
2 Plants from a slightly to strongly
woody caudex , perennial herbs.
3 Fruits (1-) 2-3 mm long, slightly
pubescent on the exterior;
petals 3.5-6.5 (-7.5) mm long, bright yellow;
ovules 4 per
ovary (flower)
3 Fruits (2-) 3-10 mm long,
glabrous (or
papillose ) on the exterior;
petals 4.5-15 mm long, variously white, pale yellow, bright yellow, or orange;
ovules 8-32 (-40) per
ovary (flower).
4 Hairs of the stems with
rays fused (
webbed ) > 1/2 their lengths
4 Hairs of the stems with
rays not fused or only fused basally.
5 Petals white, (9-) 11-15 mm long
5 Petals yellow, yellow-orange, or orange (or mixtures of those colors), 4.5-12 (-14) mm long.
6 Hairs of the stems asymmetrical, with a deep notch on one side, often with a U-shped gap between 2 of the
rays
6 Hairs of the stems symmetrical, not notched.
7 Stem leaves
ascending ,
appressed , and strongly overlapping;
ovules 16-32 per
ovary (flower)
7 Stem leaves spreading, not overlapping;
ovules 8-16 per
ovary (flower)
2 Plants from a fine
taproot , annual or
biennial herbs (or sometimes perennial in
P. gordonii ).
8 Petals pale yellow, yellow, orange-yellow, or orange.
9 Stem leaves similar in shape to the
basal leaves.
10 Ovules 4 per
ovary (flower);
silicles sessile or with
stipes (
gynophores ) < 0.5 mm long
10 Ovules 8-20 (-28) per
ovary (flower);
silicle stipes (
gynophores ) 0.5-2 mm long.
11 Pedicels sigmoid (S-shaped) in fruit;
silicle stipes (
gynophores ) 0.5-1 mm long
11 Pedicels straight or slightly curved in fruit;
silicle stipes (
gynophores ) 0-2 mm long.
12 Stems to 7 dm tall;
blade margins of stem leaves usually deeply
dentate , rarely
repand ;
silicle stipes <0.5 mm long;
silicles globose or
subglobose , 3-6 mm, the
base rounded
12 Stems usually < 3 dm;
cauline leaves:
blade margins of stem leaves frequently
repand , occasionally
dentate ;
silicle stipes 1-2 mm long, slender;
silicles obpyriform to narrowly
obovoid , (5-) 6-9 mm long, the
base truncate
9 Stem leaves different in shape than the
basal leaves.
13 Pedicels straight, curved upwards, or
sigmoid (S-shaped) in fruit.
14 Ovules 4 per
ovary (flower);
petals pale yellow
14 Ovules 8-16 (-20) per
ovary (flower);
petals bright yellow to orange.
15 Fruit
valves densely
papillose on their outer surfaces
15 Fruit
valves glabrous on their outer surfaces.
16 Pedicels straight or slightly upcurved in fruit