Flowering pattern, flowering phenology, and mating system of the closely-related, interfertile
species Penstemon tenuiflorus and P. hirsutus are the same. Flowers are protandrous, but …

Ecological life cycles, growth characteristics, and flowering requirements of the two closely-
related species Penstemon tenuiflorus and P. hirsutus were compared via a combination of …

The floral ecology of Penstemon cobaea Nutt. var. cobaea, P. cobaea var. purpureus
Pennell, P. digitalis Nutt. ex Sims, P. grandiflorus Nutt., P. pallidus Small, and P. tubaeflorus …

Penland's beardtongue, a rare endemic plant of the Colorado Plateau, displays a mixed
breeding system. Plants are partially self-compatible but set more fruits when cross …

Sagittaria (" arrowhead", Alismataceae) is a cosmopolitan monocotyledonous genus of
aquatic herbs. Five species occur in California, where Sagittaria montevidensis ssp. calycina …

According to the “effective pollination” hypothesis, tall stature resulting from strong apical
dominance attracts greater pollinator visitation, thus allowing larger pollen loads and/or …

Floral development from initiation of primordia through anthesis was studied for three closely
related species of Agalinis. Objectives were to determine the developmental basis for the …

Nectarless, rostrate flowers of Pedicularis attollens and P. groenlandica exhibited
reproductive dependence on Bombus bifarius nearcticus, B. flavifrons dimidiatus, and B …

A new subgenus of Penstemon, Habroanthus, is named to receive all Pensternon species in
which the anther sacs dehisce from the base toward the apex, usually incompletely. The …

I examined the reproductive biology of Harrington's Penstemon, a rare endemic of the
Colorado Plateau, to obtain information important to conservation efforts for this species. I …