Rayjacksonia aurea

(A. Gray) R. L. Hartman & M. A. Lane

Amer. J. Bot. 83: 369. 1996.

Common names: Houston camphor-daisy
EndemicConservation concern
Basionym: Haplopappus aureus A. Gray Mem. Amer. Acad. Arts, n. s. 4: 76. 1849 (as Aplopappus)
Synonyms: Machaeranthera aurea (A. Gray) Shinners
Treatment appears in FNA Volume 20. Treatment on page 438.

Annuals, 20–100 cm, herbaceous. Leaf-blades linear to linear-oblanceolate, midcauline 1–3 (–4) mm wide. Heads on short, sometimes bracteate peduncles, not surpassed by distal leaves. Involucres 4–7 × 10–15 mm. Phyllaries in 4–5 series, tightly appressed, strongly unequal, apices erect to slightly spreading, ca. 1 mm wide, herbaceous. Ray-florets 14–19; corollas 6.5–9.5 mm. Disc-florets: corolla-tubes ± equaling limbs. 2n = 12.


Phenology: Flowering Oct–Nov(–Dec).
Habitat: Sand or sandy loam, fields, pastures, usually relatively bare sites
Elevation: 0–10 m

Discussion

Of conservation concern.

Rayjacksonia aurea is now restricted to a few, small populations in the vicinity of Houston. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.
... more about "Rayjacksonia aurea"
not tailed +, rounded +  and obtuse +
distinct +
erect +  and slightly spreading +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
subcorymbo-cymiform +  and paniculiform +
indeterminate +  and determinate +
Guy L. Nesom +
(A. Gray) R. L. Hartman & M. A. Lane +
decurrent +
Haplopappus aureus +
linear;oblanceolate +
rugulose +  and muricate +
Houston camphor-daisy +
not 2-lipped +  and actinomorphic +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.95 cm9.5 mm <br />0.0095 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
compressed +, less columnar +  and prismatic +
fertile +  and bisexual +
fertile +  and bisexual +
compressed;broadly ellipsoid;clavate +
0–10 m +
strigoso-sericeous +, glandular +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sand or sandy loam, fields, pastures, usually relatively bare sites +
indeterminate +
heterogamous +  and homogamous +
taprooted +  and sessile +
stipitate-glandular +  and glabrous +
each +  and sessile +
thick-flattened +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
hemispheric +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
linear;linear-oblanceolate +
sessile +  and subpetiolate +
triangular +
entire +  and serrate +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
2-carpellate +
persistent +
Flowering Oct–Nov(–Dec). +
Amer. J. Bot. +
3-angled;broadly ellipsoid;obovoid +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
Endemic +  and Conservation concern +
erect +  and decumbent-ascending +
appendaged +  and truncate +
papillate +  and smooth +
Machaeranthera aurea +
Rayjacksonia aurea +
Rayjacksonia +
species +
ampliate +
spreading +  and reflexed +
linear +  and lanceolate or ovatelanceolate +
subequal +
white-indurate +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
tree +, shrub +  and subshrub +