Plant of the day is Helianthus winteri or Winter's sunflower
Pictured: Helianthus giganteus
I'm back! Good to be back. Semester is over, grades are in, and now to spend some of that extra time putting it back into plants.
Why the image of Helianthus giganteus when we're talking about H. winteri? Well, it seems every cool person in California like to copyright all the images of the plant and not commons share anything. So here is a link for the CalPhotos gallery. Some fantastic shots and a lot of detail on this.
Taxonomy, etc: I'm not going to spend a WHOLE lot of time here, it is an Asteraceae so it's in a huge family. The Helianthus genus is about 70 species and also contains the famous Jerusalem artichoke or H. tuberosus ...which has nothing to do with being an artichoke. Your standard domesticated sunflower is also H. annuus. There are a few endangered species, H. verticillatus and H. winteri being a couple of them. Definitely worthy of noting that this species was just recently described in 2013! New plants everywhere to find! If you'd like to see the full details on the description and locality see the link below. Easier than me explaining. It is very well done actually, a very nice paper. The paper also peaks some interest for use in hybridization due to several desirable traits in seed oil content and may have more lignins than cultivated sunflowers. Cool stuff.
Description: One trait I will definitely be looking for as my young plants get larger is the seeping of resin that occurs on the stems. Cross sections of the stems also don't have similar pith formation to the annual species H. argophyllus. The stem is quite woody really and can reach up to 2in or 6cm wide. They can get quite tall as well, I came across a claim of 4m! I cannot easily find a botanical description (which is annoying). From what I can tell..stems and leaf veins are slightly tomentose (fuzzy). Fairly sharp leaf margins with a deltoid shaped leaf. Honestly, if you're in a small chunk of Fresno around some really steep hills and you see some giant woody sunflowers with resin on their stems...probably going to be H. winteri. Ohh, it also flowers year round, which is pretty cool. The downside to this, however, is that the first years growth is almost indistinguishable from H. annus.
Check out some amazing stained slides of stems from http://www.brookmoyers.com/research.html
Habitat/Culture: See the link below for an actual map and an idea for just how small an area this inhabits. The area of occupancy looks like a Tetris chunk...I miss Tetris. It is found adjacent to highway 180 east of Fresno. It grows in an area that only receives about 11 inches of rainfall annually and it grows on some pretty brutally steep hillside. It's a tough plant to be sure. I'm probably way over-pampering mine. Threats to its habitat include grazing, agriculture, and road maintenance.
Propagation: I'm growing this fairly easily from seed in tall (6 inch) narrow pots to promote taproot development. I sowed them in a 50/50 blend of a barky perennial mix and haydite (for drainage), VERY lightly covered with vermiculite to hold some moisture around the seeds and sowed on a mist bench with bottom heat with day temps about 75 and night temps 65. Have to record my germination yet but I would estimate somewhere around 20% (sunflowers can be low...but it could be a problem with seed storage or my method as well).
