FAMILIES OF PLANTS 
139 
heads, like those of the dandelion, are borne on naked stems. This 
is the genus Agoseris of most authors. The five species found in the 
park may be distinguished as follows : 
1. Flowers orange, drying purple. 2. 
1. Flowers yellow. 3. 
2. Plants usually more than 8 inches high. Leaves with long, slender petioles 
Troximon purpureum. 
2. Plants usually less than 8 inches high. Leaves sessile or with short petioles. 
Troximon aurantiaoum . 
3. Leaves more or less hairy. Troximon villosum. 
3. Leaves smooth or nearly so. 4. 
4. Leaves distinctly 2-ranked. Troximon glaucum. 
4. Leaves not 2-ranked. Troximon parviflorum. 
Dandelion (Taraxacum officinale). —This is the common dandelion 
with which everyone is familiar. 
Taraxacum mexicanum is very similar but is usually smaller and 
the leaves are narrower and have a small terminal lobe. 
Taraxacum dumetorum has leaves that are irregularly toothed and 
cut but not deeply lobed like those of the common dandelion. 
Taraxacum scopulormm is a dwarf, alpine plant found only on 
the highest mountains. 
Redseed dandelion (Taraxacum erythrospermum) has also been re¬ 
ported in the park. 
Macronema grindelioides is a small, much-branched shrub, 4 to 8 
inches high, with oblong or spatula-shaped, more or less fleshy 
leaves and heads of yellow disk flowers and 6 to 12 rather conspicu¬ 
ous ray flowers. The pappus conspicuous of numerous hairlike 
bristles. The plant is found on high mountain peaks. 
Macronema lineare also occurs in the park. It has somewhat the 
habit and appearance of rabbitbrnsh but the heads contain no ray 
flowers. 
Matricaria matricarioides has been introduced in some parts of 
the park. 
Aplopappus parryi. —A leafy plant y 2 to iy 2 feet tall, somewhat 
sticky above. The upper leaves are sessile. The pale yellow flowers 
are in numerous heads surrounded by an involucre of about 3 mod¬ 
erately unequal ranks. 
Aplopappus multicaulis has also been reported in the park. It 
is very dwarf and tufted, and bears only 3 or 4 leaves and few heads 
of yellow flowers. 
