- ISBN 0-7153-0550-6 Nold, Robert.
Penstemons.
Timber Press. 1999. ISBN 0-88192-429-6 Lindgren, Dale T.
Growing penstemons : species, cultivars, and hybrids...
- one of the few
scented penstemons. The plant, in the
family Plantaginaceae, is
named after the
botanist Edward Palmer.
Penstemon palmeri is
native to desert...
-
consists of
clusters of
tubular blue to
purple flowers.
Penstemon serrulatus is one of the few
penstemons to
occur at low
elevations along the
Pacific Northwest...
-
Penstemon harringtonii,
commonly known as Harrington's
penstemon and Harrington's beardtongue, is a
species of
perennial flowering plant in the family...
-
Penstemon barbatus,
known by the
common names golden-beard
penstemon, and
beardlip penstemon, is a
flowering plant native to the
western United States...
- gardener's
guide to
growing penstemons.
Newton Abbot (England):
David & Charles. p. 82. ISBN 0-88192-424-5. Nold,
Robert (1999).
Penstemons (1st ed.). Portland...
- 2025. Lindgren, Dale Tennis; Wilde, Ellen;
American Penstemon Society (2003).
Growing Penstemons : Species, Cultivars, and
Hybrids (First ed.). Haverford...
-
Species in the
genus Penstemon are
commonly called penstemons or
beardtongues in English, and they will
often have a
common name
based on either. As the...
- (2003).
Growing penstemons : species, cultivars, and hybrids. Haverford, PA:
Infinity Pub. pp. 91–92. ISBN 0741415291. "
Penstemon virens". Navigate...
-
closely related mat
penstemon or Thompson's
beardtongue by the
penstemon experts David Way and
Peter James. As is
typical of
penstemons, they
require well...
