Helianthus arizonensis

R. C. Jackson

Brittonia 15: 266, fig. 2. 1963.

Common names: Arizona sunflower
Endemic
Treatment appears in FNA Volume 21. Treatment on page 168. Mentioned on page 145.

Perennials, 20–30 cm (roots creeping). Stems erect to ascending, glabrous (glaucous). Leaves cauline; opposite; sessile; blades (bluish green) lanceolate, 2–7 × 0.5–1.3 cm, bases cuneate, margins entire (undulate), faces glabrous (glaucous). Heads 1–7. Peduncles 2–7.5 cm. Involucres hemispheric, 9–18 mm diam. Phyllaries 16–19, lanceovate, 3.5–7 × 2–2.8 mm, (margins ciliate) apices acute, abaxial faces glabrate, sparingly glanddotted. Paleae 5.5–6.5 mm, 3-toothed (apices acute, glanddotted). Ray-florets 10–14; laminae 7–9 mm. Disc-florets 30+; corollas 3–3.5 mm, lobes yellow; anthers reddish-brown, appendages brownish. Cypselae 2.8–3.2 mm, glabrous; pappi of 2 deltate, erose scales 1–1.7 mm. 2n = 34, 51.


Phenology: Flowering summer–fall.
Habitat: Open pine woodlands
Elevation: 1200–2100 m

Discussion

Helianthus arizonensis is morphologically similar to the polyploid H. ciliaris; H. arizonensis is diploid (or triploid) and has entirely yellow disc corollas. It is known from relatively few sites.

Selected References

None.

Lower Taxa

None.
... more about "Helianthus arizonensis"
not tailed +, rounded +  and obtuse +
reddish-brown +
pale +  and dark +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
spiciform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Edward E. Schilling +
R. C. Jackson +
cuneate +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
lanceolate +
0.5cm;1.3cm +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Arizona sunflower +
reddish +  and yellow +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
compressed +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +  and N.Mex. +
1200–2100 m +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Open pine woodlands +
in more or less corymbiform , paniculiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.9 cm9 mm <br />0.009 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
hemispheric +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
triangular +
2-carpellate +
3-toothed +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
persistent +
coroniform +
2 cm20 mm <br />0.02 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
Flowering summer–fall. +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
16 +  and 19 +
0.2 cm2 mm <br />0.002 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
deltate +
0.1 cm1 mm <br />0.001 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
exalbuminous +
procumbent +  and decumbent +
erect +  and ascending +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus arizonensis +
Helianthus +
species +
campanulate +
toothed +  and entire +
300 cm3,000 mm <br />3 m <br /> (500 cm5,000 mm <br />5 m <br />) +
20 cm200 mm <br />0.2 m <br /> (30 cm300 mm <br />0.3 m <br />) +
shrub +  and subshrub +