Arabis holboellii
 
Reflexed Rock Cress

Fruiting Inflorescence

Hidden Valley
Approx. 15 mi. North of Regina at Qu'Appelle Valley
13-May-06

bullet

Holboellii:  Answers to key questions in Budd's Flora (BF) and Flora of Alberta (FOA) leading to this species.  
bullet

plants mostly well over 3 dm tall; NOT [plants mostly under 2 dm tall]

bullet

pubescence of the lower stem often stellate to dendritic; NOT [pubescence (if any) of the lower stem simple to bifurcate, often appressed]

bullet

hairs more freely branched; NOT [hairs of the lower stems and leaves predominantly trifurcate]

bullet

basal leaves mostly with trifurcate to stellate or dendritic hairs; NOT [basal leaves with malpighiaceous hairs]

bullet

pubescence of basal leaves felty

bullet

pods always sharply reflexed and pendulous; NOT [pods in part spreading, in part descending], NOT [pods spreading, never reflexed or pendulous], NOT [pods erect or  ascending, often tightly appressed]

bullet

siliques 1.5-2.5 mm broad; NOT [siliques less than 1.5 mm broad], NOT [siliques 2-3 mm broad]

bullet

seeds mostly uniseriate; NOT [seeds biseriate]

bullet

wing of seed between 0.3 and 0.5 mm wide; NOT [seeds wingless or the wing less than 0.3 mm wide], NOT [wing of seed nearly 1 mm wide]

 
bullet

Arabis: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.   The answers do not necessarily apply to all members of Arabis found on the Canadian prairies, but they all do apply to A. holboellii.
bullet

plants generally NOT glaucous

bullet

plants pubescent; NOT [plants glabrous]

bullet

plants with pubescence mostly or entirely of branched hairs; NOT [plants with pubescence of simple hairs]

bullet

leaves more or less entire; NOT [leaves deeply serrate to pinnate]

bullet

cauline leaves auriculate, clasping

bullet

flowers much smaller than 20-25 mm across

bullet

petals white, pink-tinged, pink or purple; NOT [petals yellow]

bullet

pods usually at least 4 times as long as wide; NOT [pods usually not more than 3 times as long as wide]

bullet

pods strongly flattened; NOT [pods round in cross section]

bullet

pods NOT compressed at right angles to the central partition

bullet

pods scarcely beaked; NOT [pods with a long, distinct beak]

bullet

central partition entire; NOT [central partition with an opening sometimes almost reduced to the margin]

 
bullet

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

herbs; NOT [shrubs or trees]

bullet

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

bullet

plants NOT with colored milky juice

bullet

plants with more than one normal leaf

bullet

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

bullet

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

bullet

flowers with two floral rings, and with each petal distinct from the others

bullet

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

bullet

sepals 4

bullet

corolla regular in shape

bullet

petals 4; NOT 5

bullet

stamens usually 6, four long and two short; NOT [stamens 6, of equal length], NOT [stamens usually more than 10]

bullet

ovary superior; NOT inferior

bullet

carpels 1 or 2; NOT [carpels 3-5]