Thursday, April 5, 2018

Senna splendida 'Golden'


End of last year brought this new tree to me when I was walking near Balboa Park. It stopped me in my tracks it was so beautiful! Good thing I was not in my car or I might have had an incident. Imagine a tree in almost full bloom at Christmas time that is not a camellia. It took me a little sleuthing to figure out just what Cassia or Senna it is, and it took me a little while longer to find out who grows it. 
Senna splendida 'Golden'                                                                                                             S. Reeve
This lovely tree is Senna splendida 'Golden'. It is a Monrovia exclusive. It is impossible to find otherwise, and believe me I tried! Thank goodness Monrovia decided to put it back into production and I was able to order it. Walking around my yard looking for the perfect spot. You know how that is! Anyway, I admit, I have a tree problem and not enough sunny locations for all of them. It would be better if I could confine myself to cute little succulent gardens, but no. I like this one limbed up as opposed to the massive shrub-like version that happens naturally. 

Unpruned Senna splendida or golden wonder senna straight species

This is plant is rated USDA Hardiness Zones 9-11. In Zone 8 it is a fairly reliable die-back shrub. In colder parts of its range it defoliates in the winter. Senna bicapsularis is another favorite of mine, but everything about Senna splendida 'Golden' is bigger, the leaves and the flowers are much bigger. The flowers of 'Golden' are richer in color with orange tones. Because the flower petals are thicker and more coriaceous the flower are more substantial and opaque. There is much more of a "wow" factor with 'Golden'. 
Here is a comparison of foliage from Senna bicapsularis and Senna splendida 'Golden'. Senna bicapsularis is bipinnate with roundish leaflets that are a little over an inch to two inches in diameter. Senna splendida 'Golden' also has bipinnate leaflets but each leaflet is lanceolate, around 6-inches in length, and comes to an extremely pointed apex. From what I am seeing the straight species of Senna splendida is similar to Senna bicapsularis and the selection of 'Golden' is much different. Either that or there are a bunch of mislabeled plants out there. I am not sure if the confusion is because the common name of the plant is Golden Wonder Senna and the selection made by Monrovia is Senna splendida ' Golden'? If someone can clear this up for me I would appreciate it. Look at how much different the foliage is. San Marcos Growers has a selection of Senna splendida called 'Ray's Splendor'. I have their comparison of their Senna splendida 'Ray's Splendor' and Monrovia's Senna splendida 'Golden' and they are also very different. Monrovia's plant does not resemble other photos of Senna splendida that I have seen. 
Senna splendida 'Golden' from Monrovia

Senna bicapsularis
San Marcos Growers photo
See what I mean about the foliage? Weird. These are much different and they are supposedly the same species. I did find a photo in a reference book called, "Trees and Shrubs" put out by the Armand Bayou Nature Center, that has more pointed foliage like Senna splendida 'Golden' so I am wondering if San Marcos has a Senna bicapsularis instead. While the foliage is more lanceolate in the 'Trees and Shrubs" book, it is still not nearly as large in scale as Senna splendida 'Golden'. Notice the visiting carpenter bee. They love this plant too! 
Senna splendida species

One important fact for me is that both Senna bicapsularis and Senna splendida are both favored as host plants by the Cloudless Sulphur batterfly or Phoebis sennae. I love to feed the wildlife and strive to have any host plant that can benefit neighborhood Lepidoptera. I have noticed that these well-camouflaged caterpillars are golden yellow with green bands, and they appear more yellow when feeding on yellow flowers, and greener when feeding on leaves. Don't know if these caterpillars have super powers or if there is anything to this scientifically, but I wouldn't put anything past Mother Nature. The heart-shaped chrysalis initially blends into the green leaves, but as it matures it turns pink. The caterpillar attaches the end of the chrysalis to the plant, and additionally, tethers the plant at the midpoint. It looks like a really precarious arrangement but it works--no doubt. 
Jim P. Brock 2010
We will see if the more leathery and substantial foliage of Monrovia's Senna splendida 'Golden' will appeal to them too. 
Senna splendida 'Golden'                                             S. Reeve
Notice the orange tones to the golden flowers of Senna splendida 'Golden'. Like other Sennas this tree reblooms continually throughout the blooming season and is extremely long-blooming, especially if it is sited where no freezes occur. This plant needs full sun and seems to thrive in heat. Well-drained soil is also a requirement. I am not sure if this plant is as drought tolerant as Senna bicapsularis, but I doubt it since it is native to Brazil. I am reading that this plant should be pruned severely after flowering to reduce the seed pods. I will let you know. I am super excited about getting this wonder in the ground and look forward to fall blooms later this year.






Sunday, April 1, 2018

Sweet South African Surprise-- Hymenolepis crithmifolia

Klair 2013- Green Planet

Many great plants for our California gardens come from South Africa, particularly from the Western Cape because they have a very similar summer-dry climate to San Diego.  One such treasure is Hymenolepis crithmifolia. Before that it was called Hymenolepis parviflora, and before that, Athanasia parviflora, or simply Golden Coulter Bush. Those botanists! Always renaming plants and making me learn new names when I had the old ones down pat. This is considered a shrub and is from the magical Western Cape of South Africa. The botanical description has the shrub reaching 2.5 meters with densely branched stems in the upper half of the plant. Most garden references list this plant as 1 meter or 3-4 feet tall. The leaves are super dissected or pinnatisect, with hair-like leaflets that start more of a silver/gray and mature as green. As fine as the foliage is, it is still leathery and sturdy. It seems that this progression is not in every plant. My plant stays much more gray-foliaged than green compared to some I have seen. I wonder if it has anything to do with the lack of water it gets from me? Here is a drawing from the South African Journal of Botany March 2014. Notice the individual fine-dissected leaf on the bottom left. Of the eight species in South Africa, Hymenolepis crithmifolia is the most common. 
A taxonomic revision of Hymenolepis (Asteraceae, Anthemideae) S. L. Magoswana and A. R. Magee

In a form of convergent evolution, this looks like a giant yarrow or Achillea. Funny how similar climates bred evolutionarily the same answers in plant form in Africa and also in coastal California. They have Hymenolepis 
crithmifolia and we have Achillea millefolium. 
Both plants have the tiny masses of mildly fragrant discoid flowers held at the ends of compound heads that are highly attractive to an assortment of bees, flies, and other pollinators. I like to just sit and watch the broad assortment of insects that love these flowers. So many are attracted to them. It is a regular golden dinner plate with tiny insects crawling all over the dense blooms. This evergreen plant blooms for several months in late spring/early summer. The blooms are lighter yellow when new and progress to golden yellow after a couple of months. After blooming you can cut it back to three feet to keep it garden-worthy. 
Silver gray foliage in my garden                                                                                                              S. Reeve

As you know silvery foliage and golden yellow flowers look great with many other plants. Think of foliage harmoney and juxtapose this with larger greener leaves. Combine with Lavender, Salvia x 'Anthony Parker', Salvia x 'Amistad', Cistus, Iochroma, Leonotis, and other Mediterranean plants. Golden Coulter Bush looks great with California natives like silvery foliaged Salvia leucophylla or Salvia 'Bee's Bliss'. I can see it skirting a Ceanothus x 'Ray Hartman tree or combined with Muhlenbergia rigens or 'Blue Glow' Agaves. What an exciting plant! So many possibilities for Hymenolepis crithmifolia. So much to like and so easy to care for. Prefers full sun, well-drained sandy loam soil and infrequent watering. I barely water mine, but it could be much fuller and more floriferous if I did. This plant is not frost tolerant preferring USDA Zones 9-11. Gophers and rabbits have shown no interest in nibbling on this plant. It handles the heat of late summer with no problem. It can reseed if you actually water with any regularity, which I don't. I am surprised this plant is not more well known and not more in use in San Diego Gardens. It is a lovely plant popular with pollinators, it combines well with others, which makes it a good plant in my garden.
Annie's Annuals                                                                                                                                  Annie Hayes