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Populus fremontii subsp. fremontii

ALAMO or FREMONT COTTONWOOD


Higher Taxonomy
Family: SalicaceaeView DescriptionDichotomous Key
Common Name: WILLOW FAMILY
Habit: Shrub, tree; dioecious (monoecious). Stem: trunk < 40 m; wood soft; bark smooth, bitter; buds scaly. Leaf: simple, alternate, deciduous; stipules generally present, deciduous or not, often large. Inflorescence: catkin [or various, or flowers 1]; each flower subtended by 1 bract. Flower: perianth modified into non-nectariferous, cup- or saucer-shaped structure or reduced to adaxial nectary (rarely also with abaxial nectary, then free or fused into shallow cup). Staminate Flower: stamens 2--many. Pistillate Flower: pistil 1, ovary superior to 1/2-inferior, chambers generally 2--4, placentas parietal, stigma lobes 2--4. Fruit: berry, drupe, or 2--4-valved capsule. Seed: often with basal tuft of hairs.
Genera In Family: 58 genera, 1210 species: widespread in tropics, northern temperate, arctic. Note: Now including many genera (e.g., Flacourtia, Idesia, Xylosma) formerly in Flacourtiaceae, at least in part because of presence on leaf margins in both families of salicoid teeth (vein extending to tooth tip). In California (and generally outside California), Populus pollinated by wind, Salix by insects, wind. Hybrids common; identification often difficult.
eFlora Treatment Author: John O. Sawyer, Jr., except as noted
Scientific Editor: Thomas J. Rosatti.
Genus: PopulusView DescriptionDichotomous Key


Common Name: COTTONWOOD
Habit: Tree. Stem: < 40 m; young bark smooth, pale yellow-green to gray; older bark furrowed, brown to gray; twigs with swellings below leaf scars; winter bud generally resinous, scales > 3. Leaf: juvenile, adult, late-season leaves may differ in size, shape, hairiness; generally glabrous; blade 3--11 cm, elliptic to deltate, veins pinnate or +- palmate, tip generally elongate. Inflorescence: catkin pendent, 3--8 cm; bract cut into narrow segments; flowers sessile; nectary a cup- or saucer-like disk. Flower: perianth modified into non-nectariferous, cup- or saucer-shaped structure. Staminate Flower: stamens 8--60. Pistillate Flower: style short, stigmas 2--3(4), large, scalloped to 2-lobed. Fruit: spheric to conic; valves 2--3(4), 3--12 mm.
Etymology: (Latin: name for plants of this genus)
Reference: Hamzeh et al. 2006 J Torrey Bot Soc 133:519--527
Unabridged Reference: Hamzeh & Dayanandan 2004 Amer J Bot 91:1398--1408
Populus fremontii S. Watson subsp. fremontii
NATIVE
Habit: Tree < 20 m; crown wide. Stem: twigs yellow, gray in age, glabrous to hairy; winter buds resinous. Leaf: petiole 1/2 to = blade, laterally compressed; blade 3--7 cm, deltate, yellow-green, glabrous to hairy, often stained with milky resin, base +- cordate to truncate, tip +- tapered, margin coarsely scalloped.
Ecology: Scattered. Alluvial bottomland, streamsides; Elevation: < 2000 m. Bioregional Distribution: CA (exc MP); Distribution Outside California: to central Rocky Mountains, northern Mexico. Flowering Time: Mar--Apr Note: Hybrids with Populus trichocarpa (Populus ×parryi) reported from California.
Synonyms: Populus deltoides Bartram ex Marshall var. fremontii (S. Watson) Cronquist; Populus fremontii var. arizonica (Sarg.) Jeps.; Populus fremontii var. macdougalii (Rose) Jeps.
Jepson eFlora Author: John O. Sawyer, Jr.
Reference: Hamzeh et al. 2006 J Torrey Bot Soc 133:519--527
Unabridged Reference: Eckenwalder 1977 J Arnold Arbor 58:193--208
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Populus angustifolia
Next taxon: Populus nigra

Botanical illustration including Populus fremontii subsp. fremontiibotanical illustration including Populus fremontii subsp. fremontii


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Citation for this treatment: John O. Sawyer, Jr. 2012, Populus fremontii subsp. fremontii, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=52463, accessed on December 03, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on December 03, 2024.

Populus fremontii subsp. fremontii
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©2002 California Academy of Sciences
Populus fremontii subsp. fremontii
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©2009 Keir Morse
Populus fremontii subsp. fremontii
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©2009 Keir Morse
Populus fremontii subsp. fremontii
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©2020 Neal Kramer
Populus fremontii subsp. fremontii
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©2010 Neal Kramer

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Geographic subdivisions for Populus fremontii subsp. fremontii:
CA (exc MP)
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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 occurrence).






 

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 Flowering-Fruiting Monthly Counts

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).