Jensia

B. G. Baldwin

Novon 9: 464. 1999.

Etymology: For Jens Christian Clausen, 1891–1969, Californian botanist
Treatment appears in FNA Volume 21. Treatment on page 301. Mentioned on page 255, 300, 302.
 TaxonIllustrator 
FNA21 P47 Harmonia hallii.jpegHarmonia hallii
Anisocarpus madioides
Jensia yosemitana
Marjorie C. Leggitt
Yevonn Wilson-Ramsey
Barbara Alongi

Annuals, 5–60 cm (self-incompatible). Stems erect. Leaves mostly cauline; proximal opposite (often crowded), distal alternate; sessile; blades spatulate to linear, margins entire or toothed, faces hirsute to strigose (distal leaves sometimes stipitate-glandular as well). Heads radiate, in ± umbelliform arrays. Peduncular bracts: pit-glands, tack-glands, and/or spines 0. Involucres ± obconic or urceolate to globose, 3–5 mm diam. Phyllaries 2–12 in 1 series (lanceolate to lance-attenuate, herbaceous, each usually wholly enveloping a ray ovary, abaxially hirsute, hair tips ± uncinate). Receptacles flat to convex, glabrous or setulose, paleate (paleae falling, in 1 series between rays and discs, connate, herbaceous to ± scarious). Ray-florets 2–12, pistillate, fertile; corollas yellow, sometimes purple-veined abaxially. Disc-florets 1–65, functionally staminate; corollas yellow, tubes shorter than funnelform throats, lobes 5, deltate (anthers ± dark purple; styles glabrous proximal to branches). Ray cypselae compressed, clavate, arcuate, basal attachments oblique, faces glabrous, apices beaked. Ray pappi crowns of scales (0.1–1 mm); disc pappi of 5–7 (white or purple-tipped) subulate, crisped, ciliolate scales (2.5–3 mm). x = 8.

Discussion

Species 2 (2 in the flora).

Recognition of Jensia is based on evidence that Madia in the sense of D. D. Keck (1959) is not monophyletic; the epappose annuals constituting Madia in the restricted sense are more closely related to Carlquistia than to Jensia (B. G. Baldwin 1996).

Selected References

None.

Key

1 Plants 6–60 cm; involucres urceolate or globose; ray florets 5–12, laminae 4–10 mm; discflorets 16–65 Jensia rammii
1 Plants 5–25 cm; involucres broadly obconic; ray florets 2–8, laminae 0.5–3 mm; disc florets1–7 Jensia yosemitana
... more about "Jensia"
not tailed +, rounded +  and obtuse +
pale +  and dark +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
Bruce G. Baldwin +  and John L. Strother +
B. G. Baldwin +
decurrent +
compound +  and simple +
linear to linear-elliptic +
spatulate;linear +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
purple-veined +
hairy +  and glabrous +
fusiform +, clavate +, obpyramidal +, terete +, compressed +  and obcompressed +
fertile +  and bisexual +
fertile +  and bisexual +
For Jens Christian Clausen, 1891–1969, Californian botanist +
glabrous +, hirsute +  and strigose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
less obconic or urceolate;globose +
petiolate +  and sessile +
alternate +  and opposite +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
toothed +  and entire +
2-carpellate +
persistent +
2 +  and 12 +
clavate +  and compressed +
setulose +  and glabrous +
flat;convex +
5 +  and 7 +
crisped +  and subulate +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Asteraceae (tribe Heliantheae) subtribe Madiinae +
cylindric +
toothed +  and entire +
5 cm50 mm <br />0.05 m <br /> (60 cm600 mm <br />0.6 m <br />) +
shrub +  and subshrub +