Penstemon procerus

Slender Beardtongue

Upper Inflorescence Cross Section

Centre Block, Cypress Hills Interprovincial Park

The inflorescence has been cut off near the top.  The upper portion has been discarded and the viewer is looking down at the top face of the lower portion.

The inflorescence is composed of pairs of opposite cymes (verticillasters).   The lower cymes are often pedunculate.  The upper cymes are essentially sessile, as can be seen in this photo.  Note that some authors use verticillaster to denote an entire inflorescence consisting of a spike of opposite cymes.

Note the key to the species in Budd's Flora requires stems erect or nearly so; NOT [plants decumbent to ascending].  In fact, the stems of this species can be erect, ascending, or decumbent. The rest of the answers to the key questions appear below.


Procerus: Answers to key questions in Budd's Flora (BF)  and Flora of Alberta (FOA) leading to this species. 
bulletplants herbaceous; NOT [plants shrubby, stems woody]
bulletflowers in dense terminal spikes or nodal clusters; NOT [flowers not so crowded]
bulletflowers 8-12 mm long; NOT [flowers 15-40 mm long] (BF)
bulletflowers about 1 cm long; NOT [flowers more than 1 cm long, usually at least 1.5 cm] (FOA)
bulletflowers dark bluish purple; NOT [flowers white to yellowish]



Penstemon: Answers to key questions in Budd's Flora (BF)  and Flora of Alberta (FOA)  leading to this genus.
bulletleaves NOT all basal
bulletcauline leaves opposite; NOT [cauline leaves alternate]
bulletcalyx 5-lobed; NOT [calyx 4-lobed]
bulletcorolla NOT spurred at the base
bulletfour anther-bearing stamens and 1 long sterile stamen (staminode)



Scrophulariaceae: Answers to key questions in Budd's Flora leading to this family.
bulletherbs; NOT [shrubs or trees]
bulletplants green or with some chlorophyll; NOT [plants parasitic or saprophytic, without chlorophyll]
bulletplants NOT aquatic
bulletstems NOT square
bulletleaves NOT bearing bladders
bulletflowers with two floral rings, but with the petals wholly or partly united forming a tube or bell
bulletflowers brightly colored; NOT [flowers inconspicuous]
bulletcorolla irregular; NOT [corolla regular]
bulletovary superior; NOT [ovary inferior]
bulletfruit a many-seeded capsule; NOT [fruit with 4 nutlets]