Silphium radula

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Silphium simpsonii head.jpg (43419 bytes)

Silphium simpsonii phyllaries.jpg (46054 bytes)
head--the rays of Silphium are very long.  In this genus, only the ray flowers produce fruit; the disk flowers are functionally staminate.   In most of the rest of the Asteraceae, the disk flowers alone produce fruit. phyllaries (bracts) underneath the inflorescence
Silphium simpsonii hairystem.jpg (46593 bytes) Silphium simpsonii lowerleaves.jpg (46321 bytes)
the stems in Silphium are extremely hairy, having a sandpaper feel the lower leaves of S. radula are opposite (also, do you notice how the stem appears square?); however,...
Silphium simpsonii upperleaves.jpg (45155 bytes)
...the upper stem leaves show a tendency to be alternate