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Pentagramma triangularis
GOLDBACK FERN

Higher Taxonomy
Family: PteridaceaeView DescriptionDichotomous Key

Common Name: BRAKE FAMILY
Habit: Perennial herb, in soil or on or among rocks; rhizome creeping to erect, scaly. Leaf: generally all +- alike (or of 2 kinds, fertile, sterile), generally < 50 cm, often < 25 cm; stipe generally thin, wiry, often dark, ×-section with vascular strands generally 1--3, less often many in circle; blade generally pinnate or +- palmate-pinnate (see Adiantum), often >= 2-compound, abaxially often with glands, +- powdery exudate, hairs, or scales; segments round, oblong, fan-shaped, or other, veins generally free. Sporangia: in sori or not, marginal, submarginal, or along veins, covered by recurved, often modified segment margins (false indusia) or not; true indusia 0; spores spheric, sides flat or not, scar with 3 radiating branches.
Genera In Family: +- 40 genera, 500 species: worldwide, especially dry areas. Note: CA members of Cheilanthes moved to the distantly related Myriopteris; Pellaea breweri to be moved as well, from a to-be-redefined Pellaea; traditional, often untenable limits of genera outside CA also being clarified using molecular phylogenetics.
eFlora Treatment Author: Ruth E.B. Kirkpatrick, Alan R. Smith & Thomas Lemieux, except as noted
Scientific Editor: Alan R. Smith, Thomas J. Rosatti.
Genus: PentagrammaView DescriptionDichotomous Key

Common Name: GOLDBACK or SILVERBACK FERN
Habit: Plant in soil or rock crevices; rhizome short-creeping-decumbent, generally 3--5(8) mm wide, scales lance-linear, mid-stripe dark. Leaf: stipe 5--20(32) cm, 0.5--2(3) mm wide, generally brown to red-brown (+- black); blade generally 2--3-pinnate, 2--8(15) cm, triangular or generally 5-sided, with white or yellow wax-like exudate ("farina") abaxially, with exudate or not adaxially, main axis shallowly to deeply grooved adaxially; proximal-most pinnae more strongly developed on basal side; veins free. Sporangia: along veins +- throughout abaxial leaf surface; segment margins unmodified, recurved or not.
Species In Genus: 6 species: western North America. Etymology: (Greek: 5 lines, for leaf blades) Note: Isolated within cheilanthoid ferns; most closely related to remainder of "hemionitid" clade (otherwise represented in California by Aspidotis; see Schuettpelz et al. 2007 Mol Phylo Evol 44:1172--1185; Windham et al. 2009 Amer Fern J 99:68--72). Comprises a puzzling complex of chemical, chromosomal, and morphological variants (see Yatskievych et al. 1990 Amer Fern J 80:9--17), recently recognized to include six distinct diploid lineages (treated here as species) and unnamed auto- and allo-polyploids (each diploid species except P. pallida implicated in formation of at least one allopolyploid; Schuettpelz et al. 2015 Syst Bot 40:629--644). In most plants a wax-like exudate densely covers leaves abaxially; "green-backed" plants with sparse abaxial leaf exudate tend to be sterile hybrids with malformed spores (Smith et al. 1971 Amer J Bot 58:292--299). Species descriptions and key adapted from Schuettpelz et al. (2015 Syst Bot 40:629--644).

Pentagramma triangularis
NATIVE
Habit: Rhizome tip, scales without exudate. Leaf: blade adaxially glabrous, not sticky, margins not recurved; abaxially with generally yellow to cream (white) exudate; proximal pinnae 2--6(11) cm; distal pinnae, pinnules on basal side of proximal-most pinnae pinnately lobed. Chromosomes: 2n=60, 90, 120.
Ecology: Common. Generally shaded, sometimes rocky or wooded areas; Elevation: < 2300 m. Bioregional Distribution: CA-FP, MP (caves in Lava Beds National Monument), SNE, DMtns; Distribution Outside California: to British Columbia, Idaho, Nevada, Utah, Baja California. Note: Plants with dense white (instead of yellow) exudate on abaxial blade surfaces have been treated by some as Pentagramma triangularis subsp. semipallida (J.T. Howell) Yatsk. et al.; however, such plants appear to be evolutionarily embedded within yellow exudate forms (Schuettpelz et al. 2015 Syst Bot 40:629--644). Chromosome counts from plants of both white-exudate ("semipallida") and yellow-exudate morphologies (Alt & Grant 1960 Brittonia 12:153--170; Windham & Yatskievych 2003 Amer J Bot 90:1788--1800). Based on spore size, polyploids common, including likely triploids, tetraploids, and hexaploids (Alt & Grant 1960 Brittonia 12:153--170; Schuettpelz et al. 2015 Syst Bot 40:629--644; Smith et al. 1971 Amer J Bot 58:292--299).
Synonyms: Pentagramma triangularis subsp. semipallida (J.T. Howell) Yatsk., Windham & E. Wollenw.; Pityrogramma triangularis (Kaulf.) Maxon var. triangularis
Unabridged Note: Until the study of Schuettpelz et al. (2015 Syst Bot 40:629--644) Pentagramma triangularis generally treated to include P. glanduloviscida, P. maxonii, P. rebmanii, and P. viscosa. As treated here, P. triangularis restricted to plants with glabrous adaxial leaf surfaces. These plants form an evolutionary cluster, separate from other lineages of Pentagramma, regardless of whether their abaxial leaf surfaces have yellow exudate (often recognized as P. triangularis subsp. triangularis) or white exudate (often recognized as P. triangularis subsp. semipallida). These two exudate forms---yellow versus white---not well differentiated from each other evolutionarily (Schuettpelz et al. 2015 Syst Bot 40:629--644). Even as treated here, P. triangularis is the most wide-ranging species in the genus, with extensive morphological, chromosomal and chemical variation (Alt & Grant 1960 Brittonia 12:153--170).
eFlora Treatment Author: Ruth E.B. Kirkpatrick, Alan R. Smith & Thomas Lemieux
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Citation for this treatment: Ruth E.B. Kirkpatrick, Alan R. Smith & Thomas Lemieux 2017. Pentagramma triangularis, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=77119, accessed on February 19, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on February 19, 2017.


Pentagramma triangularis subsp. viscosa
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© 2014 Keir Morse
Pentagramma triangularis
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© 2015 Julie Kierstead Nelson
Pentagramma triangularis subsp. rebmanii
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© 2014 Keir Morse
Pentagramma triangularis subsp. rebmanii
click for enlargement
© 2014 Keir Morse
Pentagramma triangularis
click for enlargement
© 2010 Julie Kierstead Nelson
Pentagramma triangularis subsp. viscosa
click for enlargement
© 2014 Keir Morse

More photos of Pentagramma triangularis in CalPhotos


Geographic subdivisions for Pentagramma triangularis:
CA-FP, MP (caves in Lava Beds National Monument), SNE, DMtns;
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.