Hesperevax acaulis var. robustior

Morefield

Syst. Bot. 17: 308, fig. 5N. 1992.

Common names: Robust evax
Endemic
Treatment appears in FNA Volume 19. Treatment on page 469. Mentioned on page 468, 470.

Plants mostly 2–7 cm. Stems 1 (–7), ± erect; branches usually 0. Leaves cauline, sessile or obscurely petiolate, largest (9–) 12–22 (–32) × 2–4 (–5) mm; petiole lengths mostly 0–0.8 times blade lengths; blades oblanceolate to obovate, acute to obtuse; capitular leaves erect or distally ± spreading. Heads borne singly or, sometimes, in glomerules of 2–8, largest 3–4 × 2.5–3.5 mm. Receptacles 1.4–1.9 × 1.2–1.7 mm. Pistillate paleae in 3–5 series, 2.5–4 mm. Staminate paleae: longest 2.5–3.2 mm. Functionally staminate florets 2–5 (–10); corollas 0.7–1 mm. Cypselae mostly 1–1.6 mm.


Phenology: Flowering and fruiting mid Apr–mid Jun.
Habitat: Dry slopes, flats, woodlands, chaparral, in clearings or under shrubs, often with extra moisture (swales, canyons, roadsides, path edges)
Elevation: 60–1100 m

Discussion

Variety robustior is known from the mountains of west-central California to interior southwestern Oregon (most known Oregon collections occurred before 1925). Like var. ambusticola, it tends to occur higher than var. acaulis where sympatric. Toward the south, it intergrades about equally with the other varieties (J. D. Morefield 1992c). The largest sizes described above are from a garden-grown specimen; field-collected plants from the same gathering were depauperate but otherwise typical. Variety robustior and Hesperevax sparsiflora var. brevifolia are superficially similar and have been confused; they are not known to intergrade or hybridize.

Selected References

None.

Lower Taxa

None.

"-0.8timesbladelengths" is not declared as a valid unit of measurement for this property.

truncate-penicillate;truncate +
scarious +
mostly ovate +  and lanceovate or linear +
spiciform +  and cymiform +
indeterminate +  and determinate +
James D. Morefield +
Morefield +
decurrent +
pliant to somewhat +
Stylocline acaulis +
compound +  and simple +
oblanceolate;obovate acute +
5-ribbed +, 3-ribbed +  and 2-ribbed +
muriculate +, papillate +  and smooth +
obovate;obovate;oblanceolate not gibbous flat +
spreading +  and erect +
Robust evax +
actinomorphic +
red-tipped +, purplish +, yellow +  and whitish +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
black-banded +  and brown +
not gibbous +, obovoid +  and obcompressed +
2.2 cm22 mm <br />0.022 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
largest +  and larger +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Calif. +  and Oreg. +
60–1100 m +
dull +  and more or less shiny +
winged +  and beaked +
dispersed +
Dry slopes, flats, woodlands, chaparral, in clearings or under shrubs, often with extra moisture (swales, canyons, roadsides, path edges) +
, +  and singly +
indeterminate +
1-1.5 times diams +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
homogamous +  and heterogamous +
campanulate +
largest +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
each +  and sessile +
petiolate +  and sessile +
2.2 cm22 mm <br />0.022 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
2 (?) +  and 8 (?) +
largest +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
rarely lanceovate +  and lanceolate +
2-carpellate +
staminate +  and pistillate +
persistent +
spreading +, erect +  and ascending or spreading +
spatulate;unlike +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
persistent +
Flowering and fruiting mid Apr–mid Jun. +
subequal +  and unequal +
paleate +  and epaleate +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
cylindric;conic +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
exalbuminous +
1 (?) +  and 7 (?) +
appendaged +  and truncate +
papillate +
Evax acaulis +
Hesperevax acaulis var. robustior +
Hesperevax acaulis +
variety +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (10 cm100 mm <br />0.1 m <br />) +