Lotus corniculatus

      
Bird's Foot Trefoil

Leaf Top

Ninette, Manitoba
28-July-2004

Note that the leaf is composed of five leaflets, the basal pair resembling stipules.

The lengths of the leaflets and calyx lobes in this specimen are larger than what is required in the key to the species, and suggest that this specimen is L. pedunculatus.  The presence of 7 flowers in the umbel would also support that identification.  However, I concluded that the specimen is L. corniculatus, and explain the above as being the result of wet conditions in a river valley.  In addition, Flora of the Great Plains describes this species as quite variable.  This flora also states that the umbel may contain up to 8 flowers.  The assignment of L. corniculatus is supported by the solid stem, the erect to incurved calyx lobes, and the obtuse sinus separating the two upper calyx lobes.

Note that the key to the genera in Budd's Flora requires:
     - leaves palmately divided; NOT pinnately divided
     - flowers usually solitary in the leaf axils; NOT in spikes, NOT in racemes
     - flowers about 4 mm long; NOT 10-20 mm long
for members of the Lotus genus.  However, neither of these is true for L. corniculatus.  In this species the leaves are pinnate, the flowers are in an umbellate head, and each flower can be more than 10 mm long.

Corniculatus:  Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.  

plants perennial; NOT annual

stems solid; NOT hollow

leaflets 5

leaflets pinnately arranged (the lower pair basal and resembling stipules)

leaflets 5-15 mm long; NOT 10-25 mm long

flowers in umbellate heads; NOT solitary in upper leaf axils

flowers yellow

calyx lobes incurved in bud; NOT recurved in bud

calyx lobes 1.5 -2.0 mm long; NOT 2-4 mm long

 

Lotus: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.

herbs; NOT shrubs

plants NOT cushion plants

plants NOT climbing

stems NOT twining on vegetation

leaves NOT glandular-dotted

leaflets entire; NOT [clearly toothed]

terminal leaflet normal; NOT replaced by a tendril

flowers all alike; NOT [upper flowers with petals, the lower ones apetalous]

flowers about 4 mm long; NOT 10-20 mm long

keel NOT truncate

fruit a legume; NOT a loment

 

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

herbs; NOT shrubs, NOT trees

plants terrestrial or semiaquatic; NOT aquatic

plants NOT with colored milky juice

plants with more than one normal leaf

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

leaves with stipules

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

calyx regular

flowers irregular in shape

corolla pea-like; NOT [with one petal spurred or sac-like]

stamens usually separate or partly so; NOT in a column

fruit a legume; NOT a 3-valved capsule