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Vascular Plants of California
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Pentagramma maxonii
DESERT 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.
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 maxonii (Weath.) Yatsk., Windham, & E. Wollenw.
NATIVE
Habit: Rhizome tip, scales without exudate. Leaf: blade adaxially not sticky, with sparse, minute, 0.1 mm, stalked +- yellow glands with small protuberances, abaxially with dense white exudate, often with many +- yellow or +- red glands, margins not recurved; +- as long as wide, proximal 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: Generally +- shaded sites, near rocks, boulders; Elevation: 300--1400 m. Bioregional Distribution: SnBr, SnJt, DMoj exc DMtns (south edge), DMtns; Distribution Outside California: Arizona, New Mexico, Baja California. Note: Based on spore size, polyploids also occur (Schuettpelz et al. 2015 Syst Bot 40:629--644); Windham & Yatskievych (2003 Amer J Bot 90:1788--1800) report one tetraploid chromosome count (2n=120).
Synonyms: Pentagramma triangularis (Kaulf.) Yatsk. subsp. maxonii (Weath.) Yatsk., Windham, & E. Wollenw.; Pityrogramma triangularis (Kaulf.) Maxon var. maxonii Weath.
Jepson eFlora Author: Carl J. Rothfels, Ruth E.B. Kirkpatrick, Alan R. Smith, Thomas Lemieux & Edward Alverson
Unabridged Reference: Chromosome count of 2n=60 by Yatskievych et al. (1990 Amer Fern J 80:9--17).
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Citation for this treatment: Carl J. Rothfels, Ruth E.B. Kirkpatrick, Alan R. Smith, Thomas Lemieux & Edward Alverson 2016, Pentagramma maxonii, in Jepson Flora Project (eds.) Jepson eFlora, Revision 4, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=100960, accessed on April 19, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 19, 2024.

No expert verified images found for Pentagramma maxonii.



Geographic subdivisions for Pentagramma maxonii:
SnBr, SnJt, DMoj exc DMtns (south edge), DMtns
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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).





 

Data provided by the participants of the  Consortium of California Herbaria.
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Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).