This multiplicity of characteristics gives rise to nomenclatural confusion:  Intermountain Flora and Utah Flora call the plant Haplopappus spinulosus.  Intermountain notes that "this widespread species is divisible, with some difficulty, into several geographic varieties..., var. paradoxus [shorter plants] and var. gooddingii [taller plants]".

Colorado Flora calls this plant Machaeranthera pinnatifida and Weber states that it is a "plant with many races" but Weber does not provide names for these races.  

The Synthesis of the North American Flora most recent edition of November, 2007 accepts the name Machaeranthera pinnatifida but recognizes subspecies "gooddingii" and "pinnatifida", the first of which has two varieties and the second has three varieties.  Of the seven taxa recognized by the Synthesis, five occur in the Four Corners region.  Haplopappus spinulosus variety paradoxa of Intermountain shows up in the Synthesis as Machaeranthera pinnatifida subspecies gooddingii variety paradoxus.

The Flora of North America says that Machaeranthera pinnatifida should be called Xanthisma spinulosum, as proposed in 2003 by Morgan and Hartman.  FNA recognizes five varieties of Xanthisma spinulosum: gooddingii, paradoxum, glaberrimum, chihuahuanum, and spinlosum.

Finally, the soon to be released Four Corners Flora indicates that only two species are found in the Four Corners region, Machaeranthera pinnatifida variety gooddingii and variety pinnatifida.

Some of the overlap in names does seem to indicate that the various authors are referring to the same plants, but range maps for some plants with similar names shows that different plants are probably being discussed.

In short, I think it safe to say we don't quite know what we are talking about when we discuss this plant!  I sure think the form shown in the first four photographs below is quite attractive, no matter what we name it.

Semi-desert. Openings, hillsides. Spring.
Mc Elmo Canyon, Canyons of the Ancients National Monument, April 27, 2005.

The plant at left (and in the next three photographs below) has numerous, thin, deeply lobed, intermeshed leaves.  Last year's dried flower stalks are often present.  Once new flowers appear, the plant becomes a lovely, vibrant mass of gold floating on top of silvery green leaves.  Flowers are over an inch across and the plant is quite hairy.

This plant is probably what The Flora of North America calls Xanthisma spinulosum variety spinulosum and what Four Corners Flora calls Machaeranthera pinnatifida variety gooddingii and what the Synthesis calls Machaeranthera pinnatifida subspecies gooddingii variety paradoxa.

"Machaer" is Greek for "sword" and "anther" is Greek for "flower".  Together they refer to the sword shape of the anther tips.

In 1804 Meriwether Lewis collected the first specimen of this plant on the prairies of what is now South Dakota and in 1814 Frederick Pursh named it Amellus spinulosus.

Semi-desert. Openings, hillsides. Spring.
Mc Elmo Canyon, Canyons of the Ancients National Monument, March 27, 2005.

The silvery appearance is due to innumerable soft, short, fine hairs.

Semi-desert. Openings, hillsides. Spring.
Mc Elmo Canyon, Canyons of the Ancients National Monument, March 27, 2005.

Semi-dessert. Openings, hillsides. Spring.
Mc Elmo Canyon, Canyons of the Ancients National Monument, April 27, 2005.

Semi-dessert. Openings, hillsides. Spring.
Yellowjacket Canyon, Canyons of the Ancients National Monument, October 27, 2007.

This sprawling plant with stems up to fourteen inches long is a different subspecies of M. pinnatifida from the plants shown above.  As this and the two photographs below indicate, flower heads are smaller and cylindrical rather than spherical (see the flower heads of the other subspecies above); stems and leaves have scattered, fine hairs rather than a dense wooliness; and although a few leaves are deeply cut, most have smooth (entire) margins.  The leaves of both plants are tipped in small, stiff hairs.

This plant is probably what The Flora of North America calls Xanthisma spinulosum variety paradoxum and what Four Corners Flora and Synthesis call Machaeranthera pinnatifida variety pinnatifida.

Semi-dessert. Openings, hillsides. Spring.
Yellowjacket Canyon, Canyons of the Ancients National Monument, October 27, 2007.

Phyllaries of both subspecies shown on this page are in 5-7 rows.  The phyllaries at left are somewhat glandular (sticky) as you can see by the dots of dirt adhering to them.

Semi-dessert. Openings, hillsides. Spring.
Yellowjacket Canyon, Canyons of the Ancients National Monument, October 27, 2007.

The leaf shape at upper left is the same as the leaf shape on the subspecies at the top of the page, but  most other leaves on the subspecies pictured at left have no indentations.  Leaves of either shape have very fine hairs (noticeable on their edges).