Atriplex saccaria var. saccaria

IllustratedEndemic
Synonyms: Atriplex caput-medusae Eastwood Atriplex saccaria var. caput-medusae
Treatment appears in FNA Volume 4. Treatment on page 348. Mentioned on page 347, 349.

Herbs, erect, mainly 0.5–5 dm. Leaves all petiolate or distal ones subsessile, blade cordate-ovate or subreniform to oval or ovate, 10–30 × 10–25 mm, base cordate or some only broadly truncate or less commonly rather abruptly cuneate, margin entire or rarely slightly hastate. Staminate flowers in glomerules in distal axils and in terminal, deciduous panicles. Fruiting bracteoles dimorphic, those with subglobose body bearing flattened or cristate processes borne on stipes to 10+ mm, and those mainly lacking processes, cuneate in outline, and sessile.


Habitat: Mat-atriplex, shadscale, greasewood, and pinyon-juniper communities, on fine-textured saline substrates (often semibarren) of the Bridger, Duchesne River, Mancos Shale, Dakota, Morrison, Entrada, and Chinle formations, and on fine-textured alluvium
Elevation: 1100-2200 m

Distribution

Ariz., Colo., N.Mex., Utah, Wyo.

Discussion

The main center of diversity of the Atriplex saccaria complex is in the Four Corners region. Both leaf and bracteoles profiles are almost as variable within var. saccaria as for the species as a whole. Bracteoles vary from mainly cuneate and mostly lacking processes to almost all or indeed all of them stipitate and with either flattened or hornlike appendages. The main, but still tenuous, feature used to hold this assemblage together is leaf shape, which varies around a cordate profile, with extreme on the cordate side being clearly reniform, but with variations to oval, ovate, elliptic, and triangular also being present. The triangular ones are rather common in juvenile plants. Sometimes the most extreme bracteole condition, wherein the stipes are greatly elongate and the surfaces are completely covered with large, flattened processes (simulating var. cornuta), occurs on plants with the most exorbitant cordate-reniform leaves, but these extreme forms occur within populations that also bear partially subdued processes or none at all.

There are specimens from along the San Juan River with decidedly triangular juvenile leaf blades, which otherwise produce bracteoles as within A. saccaria. They fit the original description of Atriplex caput-medusae. Miss Eastwood’s description of the fruiting bracts also clearly indicates an affinity with A. saccaria. Every degree of transition is present between plants with triangular leaves and those that are definitely cordate or reniform. There seems to be no substantial reason for recognition of additional taxa.

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

dentate +, truncate +  and undulate-dentate +
acute +  and rounded +
hornlike +, cristate +  and flat +
Stanley L. Welsh +
S. Watson +
slippery +
aromatic +
cuneate +, some +  and cordate +
Saccariae +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
subreniform +  and oval or ovate +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
subglobose +
persistent +  and deciduous +
reddish-brown +, black +, brown +  and green +
0 cm0 mm <br />0 m <br /> (?) +
cuneate +  and ovate or obovate +
not crested +
5-parted +
rounded +
Ariz. +, Colo. +, N.Mex. +, Utah +  and Wyo. +
1100-2200 m +
tuberculate +
1 +  and 3 +
unisexual +  and bisexual +
not +  and connate +
enlarged +
Mat-atriplex, shadscale, greasewood, and pinyon-juniper communities, on fine-textured saline substrates (often semibarren) of the Bridger, Duchesne River, Mancos Shale, Dakota, Morrison, Entrada, and Chinle formations, and on fine-textured alluvium +
bladderlike +
terminal +  and axillary +
opposite +  and alternate +
deciduous +  and persistent +
not winged +  and winged +
in some subhastately lobed or sometimes undulate-dentate , apex +  and entire +
hastate +  and entire +
suborbicular +  and round-triangular +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
inferior +, half-inferior +  and superior +
crassinucellate +  and bitegmic +
campylotropous +
1 +  and single +
persistent +  and deciduous +
(1-)3-5-lobed +
papery +  and chartaceous +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
cuneate +, cristate +  and flattened +
subopposite +  and alternate +
Proc. Amer. Acad. Arts +
bulbous +  and taprooted +
fusiform +
fleshy +  and fibrous +
verrucate +  and striate +
brownish +  and whitish +
flattened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Illustrated +  and Endemic +
cylindric +
3 +  and 5 +
opposite +  and alternate +
angled +  and terete +
succulent +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
sessile +  and petiolate +
reduced;small +
horizontal +  and vertical +
verrucate +
Atriplex caput-medusae +  and Atriplex saccaria var. caput-medusae +
Atriplex saccaria var. saccaria +
Atriplex saccaria +
variety +
dicotyledonous +