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Pentagramma rebmanii
REBMAN'S SILVERBACK 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).
eFlora Treatment Author: Carl J. Rothfels, Ruth E.B. Kirkpatrick, Alan R. Smith, Thomas Lemieux & Edward Alverson

Pentagramma rebmanii (Winner & M.G. Simpson) Schuettp. & Windham
NATIVE
Habit: Rhizome tip, scales without exudate. Leaf: blade adaxially not sticky, with sparse white exudate, abaxially with dense white exudate, margins not recurved; +- as long as wide, lower pinnae each +- same size as remainder of leaf, the leaf thus ternate; proximal pinnae 2--5(7) cm; distal pinnae, pinnules on basal side of proximal-most pinnae deeply pinnately lobed to +- 1-pinnate. Chromosomes: 2n=60.
Ecology: Seasonally moist, shaded, rocky slopes; Elevation: 450--1250 m. Bioregional Distribution: s PR (s San Diego Co.); Distribution Outside California: nw Baja California. Note: Appears to have formed an allotetraploid with P. glanduloviscida (Schuettpelz et al. 2015 Syst Bot 40:629--644). Chromosome number inferred from spore size; one individual matching this morphology had larger spores, and appeared to be a polyploid (Schuettpelz et al. 2015 Syst Bot 40:629--644).
Synonyms: Pentagramma triangularis subsp. rebmanii Winner & M.G. Simpson
eFlora Treatment Author: Carl J. Rothfels, Ruth E.B. Kirkpatrick, Alan R. Smith, Thomas Lemieux & Edward Alverson
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Citation for this treatment: Carl J. Rothfels, Ruth E.B. Kirkpatrick, Alan R. Smith, Thomas Lemieux & Edward Alverson 2016, Pentagramma rebmanii, in Jepson Flora Project (eds.) Jepson eFlora, Revision 4, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=101694, accessed on November 22, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017, Jepson eFlora, http://ucjeps.berkeley.edu/eflora/, accessed on November 22, 2017.


Geographic subdivisions for Pentagramma rebmanii:
s PR (s San Diego Co.);
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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Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.