I almost didn't make it to the national forest this week because I got powerfully distracted at the Bullfrog Pond. As I was climbing upslope the low- slanting morning sunlight flooded through the cattails along the pond's banks so prettily that I just had to go sit there. The chilly wind was still pretty stiff so the vertical cattail blades shivered and twisted as the sunlight filtered through them. The stems and cinnamon- brown, frankfurter-like flowering heads created black silhouettes but the thin, twisting blades generated brilliant patterns of translucencies, bright yellow- green sun-splotches, and shadowy spots. Such animation, such kaleidoscopic light, and that chill in the wind, the odor of the mud, the waves on the pond... exactly the way a cattail thicket full of hidden bullfrogs and coots should be.
Those cattails were not like the cattails I grew up with in Kentucky or lived near in Mississippi. They were not "Common Cattails," TYPHA LATIFOLIA. The blades and stems around me were noticeably narrower than what I'm used to. In fact these were a different species, the "Narrow-leaved Cattail," TYPHA ANGUSTIFOLIA. To confirm this I checked the flowering heads, for there's a trick that definitely separates the two species, and that trick is shown very nicely in the image at http://www.ibiblio.org/herbmed/pictures/p14/pages/typha-angustifolia-3.htm.
What that picture shows is a Narrow-leaved Cattail's immature flowering head. To understand the identification "trick," however, you need to know some basic facts about a cattail's flowering spike.
Mainly, when a cattail's flowering head is immature it consists of two distinct flowering zones. Below is an area composed of thousands of close-packed female and sterile flowers. Above the female flowers appears a similar region of close-packed male flowers. Typically after pollination the male flowers fall off leaving just the slender, pointed, naked axis, while the female flowers below continue growing and maturing, eventually collectively forming the brown, frankfurter-like thing that flower arrangers dry and add to their floral compositions. At maturity the brown, frankfurter-like thing is a collection of thousands of tiny cattail seeds attached to fuzzy, wind-catching "parachutes." As the winds of late fall and winter buffet the heads they disintegrate and the parachuted seeds launch into the wind.
The identification "trick" is that on the axis of the Common Cattail's flowering spike there is no naked space between the zone of female flowers and the zone of male flowers, while with Narrow-leaved Cattails there is indeed a section of naked, flowerless stem ¼ to 2 inches long. The image linked to above clearly shows that gap.
In California we actually have three cattail species, but that third one isn't found here.