OREONANA VESTITA AT WINDY GAP AND MT. WILLIAMSON,
SAN GABRIEL MOUNTAINS
MARCH 2012 PAGE ONE
Photographs by Michael Charters




This photo gallery is dedicated exclusively to a species that is often overlooked, Oreonana vestita (S. Watson) Jeps. This is only the second of my photo galleries to be so dedicated, the first being that for Chaenactis glabriuscula var. orcuttiana back in March 2010. I have chosen to do this for a couple of reasons. First, this is a species I have been looking to see and photograph in bloom for a number of years and although I have observed it many times along the bare rocky ridges of the San Gabriels, I have always been too late to see it in bloom. And second, I could only find a single picture on the internet of one in bloom, thus indicating that it is a difficult thing to find. Oreonana vestita is a CNPS 1B.3 listed species, which means that although rare, it is not particularly endangered in California because of its habitat. The two other species in California are O. purpurascens and O. clementis, both of which are residents of the high Sierra Nevadas. The plants I observed yesterday were all extremely small, no larger than a quarter, and I can't account for them being in bloom because Munz's Flora of Southern California, Abrams' Flora of the Pacific States and Jepson Manual 2 all say June to July is their blooming period. I think the reason I've never seen them bloom before is that it usually happens when the high mountain trails are blocked by snow. For a long time I puzzled over the structures that were represented in photos I had taken, but thanks to the help of Tom Chester, who studied some of my pictures and provided some clear explanations of how this plant develops, I now have a much better idea. For the first hike, I started from the Crystal Lake trailhead at the top of Route 39 north of Azusa. With much of the campground area still closed, it is a 6-mile roundtrip hike with 2200' of elevation gain. The occasional patches of snow along the trail did not do much to impede my progress, but the howling winds and what felt like freezing temperatures at Windy Gap prevented me from remaining there for long, however a dozen or so Oreonana plants were apparent in some of the bare patches of ground, and I was extremely happy to at last be able to photograph them. The second hike was to the summit ridge of Mt. Williamson where there was a great deal more snow, many places along the trail being at least 18" deep, but still Oreonanas were to be found again in the bare patches. Only the bloom and leaf pictures shown here are from these hikes, the others are from previous trips. And thanks also to Jane Tirrell for letting me know that these little treasures are blooming now.






The description for Oreonana in Abrams' Flora of the Pacific States is as follows: "Low tufted stemless plants from a stout taproot, more or less pubescent or tomentose throughout. Leaves pinnately or ternately decompound into small crowded divisions with callous margins and cuspidate tips. Umbels compound, condensed and subcapitate; involucre none; involucels one-sided. Flowers white or purplish; sepals evident. Sterile flowers on slender pedicels exceeding the rays; fertile flowers sessile. Fruit ovoid, somewhat laterally compressed; ribs filiform; oil-tubes several in the intervals and on the commissural side." The above picture shows the petals, a couple of styles, and the incurving stamens with their attached anthers between each one of the petals. The flowers are either bisexual (with styles) or staminate.


 
 
 

The picture at left above shows the tips of the bractlets poking up around the perimeter of the inflorescence. Abrams says "Bractlets numerous, lanceolate-lobed," and JM2 says "Bractlets +/- free." Actually the inflorescence is a compound umbel, an umbel of umbels (or umbellets aka involucels). There are no bracts, but the umbellets have bractlets around the side of the umbellets that faces outward. The pictures at right show more views of the bractlets.



   
Petiole bases generally sheathed
 
New inflorescence just emerging from
the ground
 
Two inflorescences on peduncles rising
from the tap root



 

I always thought that this was a larger plant, because whenever I have seen it, the peduncles have already elongated and the leaves were much more extensively developed



 

I've never exactly been sure which arises first, the leaves or the flowers. Sometimes you see leaves with no flowers as in the picture at left above, and sometimes you see flowers with no leaves, and sometimes both together.



 

The leaves are pinnately or ternately dissected with lanceolate or oblong segments. The leaf divisions have cuspidate tips that are not always obvious because they can be obscured by the dense hairs.




   
Stamens and anthers now protruding   Styles and stigmas   Tomentose peduncle



This picture shows an individual involucel or umbellet. The three non-fruiting flowers are on short pedicels, while the fertile flower is sessile.



 
Left: 5 free, spoon-shaped petals. Right: calyx lobes (or sepals) described by JM2 as inconspicuous and often obscured by hairs. The picture below shows the size of an individual flower.