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Petrophytum caespitosum

Higher Taxonomy
Family: RosaceaeView DescriptionDichotomous Key

Common Name: ROSE FAMILY
Habit: Annual to tree, glandular or not. Leaf: simple to palmately or pinnately compound, generally alternate; stipules free to fused (0), persistent to deciduous. Inflorescence: cyme, raceme, panicle, cluster, or flowers 1; bractlets on pedicel ("pedicel bractlets") generally 0--3(many), subtended by bract or generally not. Flower: generally bisexual, radial; hypanthium free or fused to ovary, saucer- to funnel-shaped, subtending bractlets ("hypanthium bractlets") 0--5, alternate sepals; sepals generally 5; petals generally 5, free; stamens (0,1)5--many, anther pollen sacs generally 2; pistils (0)1--many, simple or compound, ovary superior to inferior, styles 1--5. Fruit: 1--many per flower, achene (fleshy-coated or not), follicle, drupe, or pome with generally papery core, occasionally drupe-like with 1--5 stones. Seed: generally 1--5 (per fruit, not per flower).
Genera In Family: 110 genera, +- 3000 species: worldwide, especially temperate; many cultivated for ornamental, fruit, especially Cotoneaster, Fragaria, Malus, Prunus, Pyracantha, Rosa, Rubus. Note: Number of teeth is per leaf or leaflet, not per side of leaf or leaflet, except in Drymocallis.
eFlora Treatment Author: Daniel Potter & Barbara Ertter, family description, key to genera, treatment of genera by Daniel Potter, except as noted
Scientific Editor: Daniel Potter, Thomas J. Rosatti.
Genus: PetrophytumView Description 

Habit: Shrub, matted, scapose. Leaf: crowded, simple, evergreen, generally +- oblanceolate, entire. Inflorescence: +- spike-like; pedicel bractlets 0. Flower: hypanthium bractlets 0; sepals persistent; petals white; stamens 20--40; pistils generally 5, simple, ovary superior, hairy, styles thread-like. Fruit: follicles, dehiscing along both sutures. Seed: 1--several, linear.
Species In Genus: +- 4 species: western North America. Etymology: (Greek: rock pl)
eFlora Treatment Author: Daniel Potter & Thomas J. Rosatti

Petrophytum caespitosum (Nutt.) Rydb.
Habit: Plant 3--8 dm wide; rosettes many. Leaf: 1--3-veined abaxially. Inflorescence: 1--5 cm, dense; peduncle 3--10 cm, bracted. Flower: sepals +- 1.5 mm, narrow-ovate, acute; petals +- 1.5 mm, generally obtuse; style +- 3 mm. Fruit: +- 2 mm. Seed: 1--2, +- 1.5 mm, linear to obovoid, brown, smooth.

Synonyms: Petrophyton caespitosum (Nutt.) Rydb., orth. var.;
eFlora Treatment Author: Daniel Potter & Thomas J. Rosatti
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Key to Petrophytum caespitosum

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botanical illustration including Petrophytum caespitosum


Citation for this treatment: Daniel Potter & Thomas J. Rosatti 2012, Petrophytum caespitosum, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on September 25, 2018.

Citation for the whole project: Jepson Flora Project (eds.) 2018, Jepson eFlora,, accessed on September 25, 2018.

Petrophytum caespitosum subsp. caespitosum
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© 2005 James M. Andre
Petrophytum caespitosum subsp. caespitosum
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© 2015 Steve Matson
Petrophytum caespitosum
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© 2008 Vernon Smith
Petrophytum caespitosum
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© 2003 Michael Charters
Petrophytum caespitosum subsp. caespitosum
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© 2009 Steve Matson
Petrophytum caespitosum
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© 2000 John Game

More photos of Petrophytum caespitosum in CalPhotos

Geographic subdivisions for Petrophytum caespitosum:
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.
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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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.