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Wednesday, March 30, 2011

Acacia melanoxylon - Black Acacia

The black acacia is almost as common, maybe more so that the silver waddle, you might just not notice it as much. They remind me of large billowy masses of medium green foliage providing an evergreen background for other trees. You only really notice them when they start to bloom.

This is perhaps one of the most invasive plants in our area. You need to be careful getting mulch from tree companies as the seeds are very viable. You really don't have to go far to see young trees of this species. Luckily they are fairly short lived.

This Acacia is a large fast growing evergreen tree growing 25 - 50' or more, can be up to 90'. Eventually forms a dense rounded canopy with an overall dull green cast.




The leaves are very different than those of most other acacias in our area and in true botanical sense they are not even leaves... (I know) but really flattened petioles (the leaf stock). The true leaves (bipinnately compound) are present when very very young or occasionally on a sprouting trunk.  So the "leaves" you normally see are 2-5" long, medium green to dark green in color, straight or curved with distinct veins running parallel (an unusual arrangement for a dicot) are really petioles.




You may find them like this picture where they are transitioning to flattened petioles (call phyllodes).






The flowers are similar to other acacia in that they are clustered into heads in a raceme but like the others around here they are very light yellow. Some trees seem to be covered while others have few. Not really attractive but nice.



One thing you will notice and want to avoid is the seed heads. The fruit is a legume (a pod opening on both margins) medium brown, constricted and twisted, with flattened black seeds. The seeds have a red aril that attract birds and help move the tree.




Bark on old trees is reddish brown and shallowly furrowed. On young trees it will be green to silver gray and smooth.




Misidentification? Look at the foliage, the leaves are slightly falcate or sickle-shaped and the veins appear parallel.

Care to mention a nice specimen?

Magnolia x soulangiana - Saucer Magnolia

Magnolia x soulangiana is a hybrid (hence the x) of a common shrubby magnolia (M. liliiflora) you may see around town and M. denudata. Then, they then backcrossed it with M. liliifora back and end up with some really nice cultivars that you might see at the local nurseries. There are countless cultivars available and I doubt that the species is sold anymore.

Saucer magnolias are small deciduous trees to about 30 feet but usually nearer to 20'. They are usually branched low with lots of lateral branches extending out and upward creating a more or less rounded spreading crown.




Of course the real attraction is they bloom early in the season, with hundreds of flowers. You may see several colors or ranges of purple around. Many flowers have pale pink petal outsides with pure white insides. A common darker colored flowered cultivar with globose flowers is 'Rustic Rubra'. The common name Saucer Magnolia comes from the shape of the flower. Flowers are large, 6-8" or so, usually pink on the outside and white on the inside.




The sepals and petals look the same, you can't tell them apart. There are usually at least 8 of them. They form a cup or saucer shape. Inside the flowers are the male and female parts. The males are long and showy located below the female part, and there are lots of them. The female reproductive structures are on a elongated shoot. (The best way to see this is to look at the fruit of the southern magnolia. go to that post and see.)



In colder climates they make a larger impact in the early spring as all the flowers open all at once. In many climates it can be almost too early as a hard frost during bloom can kill all the flowers. (I visited Duke Gardens with students one spring and in North Carolina during March it was 15 degrees and all the flowers were black.)

Because we don't really have a "winter" these trees do not bloom all at once like they should, they seem to bloom for a month or longer, just fewer flowers open at a time.  When we moved back to CA our neighbor had a tree in full bloom on Christmas, what a treat and a shock. They also seem to bloom okay for a long time rather than going big.

The leaves are 3-6" long, oblong to obovate shaped with a small point at the tip. Summer color is medium green at best.  Notice the bark in this picture. The magnolia bark is attractive. Its silver gray colored and quite smooth.



An easy ID feature for magnolias is the flower bud. Large, fuzzy and terminal. Notice the young twig is reddish brown and quickly turns to gray.




This is the fruit cluster of the saucer magnolia. They don't generally produce them in larger numbers or at all. They are really a cluster of small follicles that will split open to release the orange colored seeds inside.



If it gets cold enough you might see some fall color which can be pretty nice, but is not very common.




As I mentioned there are tons of cultivars around, and with all of the hybridization going on with different species its pretty hard to tell the players without a score card. Here are a few of my favorites.

'Butterflies' is one of several yellow ones.  (M. acuminata x dentata) (see locations below)




'Alba' is a pure white one. (Seabreeze Place - corner of Sumner - RDM - hard to see)




'Vulcan' is a very dark pink cultivar (M. campbellii 'Lanarth' x liliiflora) (along Old San Jose Road)




There are yellow flowering magnolias:
Pleasure Point has a Yellow Butterfly at 918 Scriver St.

4413 Nora you can find two nice Yellow Lantern cultivars

Santa Cruz - 1324 Broadway, not sure which cultivar


Misidentify this plant? Well, trying to identify specific cultivars is tough, as well as some of the other larger saucer shaped magnolias.

If you can name it Magnolia you are doing great.


Location:
Capitola
716 Gilroy Ave is a great specimen of the normal hybrid

Santa Cruz
116 Almena Ave has one of the best Rustic Rubra cultivars seen around

Monday, March 28, 2011

Cedrus deodara - Deodar Cedar

Deodar cedars are very attractive large evergreen conifers. Younger specimens are beautiful, soft and weepy, while mature specimens are more open.

Best in parks, schools and others areas where it can be allowed to grow, however more often than not you will find them in the front yard of your neighbors house. Not hard to understand why, they have an almost hug-able texture and habit when young. Soft, weepy, graceful with a weeping leader, ahhh.



Then you wake up 10 years later and OMG what have I planted in my small front yard? Not quite the front yard but yikes

Fast growing evergreen conifer to 50' tall and about 30' wide, strongly pyramidal shape, strong central leader with outward horizontal laterals when mature, or more upright when young like in the picture above. The secondary laterals are pendulous as is the central leader adding to the soft texture. Can be up to 80 feet under great conditions, like in the pacific northwest. This is a reasonably mature specimen at the Sesnon House showing the typical habit but with greater age they will become more flat topped.




Leaves (needles) are evergreen, linear or needle like, gray-green color, 1-2" long and in clusters (spurs) of 20-40 per spur. New stems produce same needles radially around the trunk with bud in the axil of each leaf. The bud grows into the spur, each year producing leaves and losing others. Generally on a 5-6 yr rotation.



One-year shoots densely pubescent. Also showing the leaves on elongating shoots are not in clusters but that the clusters come from the lateral buds just starting to grow.




Male cones are elongated ephemeral structures lasting only long enough to release the pollen. Borne on the tops of lower branches.





Female cones are 3-4" tall x 2" wide, forming in the fall, maturing in the summer and breaking up into scales that fall to the ground, along with the seeds. The central axis remains for some time. Initially green and purplish, then later turning a reddish brown when mature, usually resinous. Cones generally rounded at the top.




Trunks straight grayish brown bark, shallowly fissured with flat ridge plates.



Many cultivars available, too many for sure, one of my favorite conifer nursery, Stanley and Sons lists at least 40.

Please give them room. This is trouble waiting to happen.



Misidentification:
More than likely a greener form of Cedrus atlantica or perhaps if you are lucky and stumble across a C. libani.

Location:

Liquidambar styraciflua - American Sweetgum

Ah yes, the poor Liquidambar, so out of its native element that it can't even drop its leaves. Native to the east-coast and down past Texas and into Mexico resulting in trees that go dormant early winter and those that wait until spring. Those grown here seem to have more of the semi-evergreen.

To illustrate this range, this is a picture taken the last week of January at the Temple Beth El on Soquel showing the variability of the trees. Notice there are 2 completely deciduous with almost identical habits, one smaller red one and a larger green/orange one behind it. (The smaller green on up against the building is not the same species. There is also a larger one behind the building showing more red and green.)



The American sweetgum is a fast growing, very large semi-deciduous to deciduous tree, up to 85' or so, but generally 40' or so here. Width is about 2/3 the height depending on the cultivar. They usually have a nice large straight truck, especially in their native habit. When young they are pyramidal. They are also bigger than most people want, so they end up getting pruned improperly. They will develop codominate stems if not watched carefully. This picture shows why an architect wants to use named cultivars, so they are all the same.


On Bay in Capitola.



The leaves are very distinct (though a cultivar called 'Rotundaloba' defies this statement). They are palmately lobed with 5 pointed lobes (sometimes 7). The lobes are finely toothed. Leaf size is about 4-7" long and wide. They somewhat resemble a maple leaf, but are arranged alternately on the stem (one per node, maples have 2 leaves at each attachment point). Summer leaves are very dark but bright green.



Flowers are clustered in heads, males and females separated spacially, like a good private school. Females are in small clusters on a short stalk.



Fruit develops from the round female cluster into a nasty little capsule. These 1" capsules are hard, sharp and prolifically produced. Sometimes called ankle bitters or ankle twisters.



Here they are covering the ground, lots of fun.



Fall color, or should I say winter to spring color can be fantastic. Reds, purples, oranges to yellows. Very beautiful and lasting a long long time. In the spring the new leaves actually have to push off the old ones. I was riding my bike about the first of April and saw what looked like a huge puple leaf plum having finished blooming, so I went to investigate, low and behold a liquidambar still with fall color.



Stems can be smooth or they can have neat looking corky ridges. The tree either has corky or not, its not something that might come along.






Very commonly planted street tree, lawn tree and such. Be very careful, it will more likely be too large for your location and they have a well deserved reputation of lifting sidewalks. Keep the trees 8-10' from any concrete to help avoid this problem.

'Festival', columnar form, light green foliage and reds to oranges in fall.

'Palo Alto', Pyramidal form, rich green leaves and bright red-orange fall color, uniformly over the whole tree, introduced by the Saratoga Horticultural society

'Burgundy' Wine red to deep purple red fall color; may persist into winter.

'Silver King' from Spokane



Misidentification:
I don't think so, some leaves might look like a maple, but maples have opposite leaves.

Location:
Santa Cruz
305 Effey is a massive specimen.

Acacia dealbata - Silver Wattle

It's really amazing how many of these trees there are here in SC. Early January the flower buds start to swell and by late January the county is alive in yellow trees!

Acacia delabata or the Silver Wattle was one of the first trees I learned in plant id class years ago at College of San Mateo. As an instructor I know well that it is often just as important to discuss the bad trees as the good ones and of course the common ones.

Why are these and others so common you ask? Well that's a good question and one that needs more time but, common trees do well, are competitive (weedy) and had some feature that was considered beneficial at one time.

The silver wattle is a fast growing medium to large evergreen to about 30-60 feet with wide spreading branches and an overall rounded habit. Often branched to the ground, often multi-stemmed. It seems to like company as it is usually growing in groves like the ones along highway 1 in Aptos.




The tree has many redeeming values of course, it is fast growing, it booms very early in the spring, the flowers are very yellow and last a very long time, maybe 30 days or more (in the spring flowers last longer if the weather is cool).

Most of the advantages also make it a weed. I have seen more trees ready to tip over that not. They seem to just "go". They have a short life span, maybe 30 years.




The foliage is an attractive silver blue green colored, alternately arranged on the stems and bi-pinnately compound. This means the leaves are divided into lots of leaflets and each leaflet is divided as well. The leaves are evergreen, 3-5" long. The lateral leaflets (8 to 20 of them) are more or less perpendicular to the main axis of the leaf. The leaflets are very small, numbering 20-40 or so on each side leaflet. The leaves are longer, wider, having more leaflets and point more forward than A. baileyana. The stems are either glaucescent or weakly tomentose and angular in cross section.



Fantastic floral display in January through February. The flowers are a very bright canary yellow, in round clusters arranged in a raceme. About 30-40 or so flowers, each about 1/4" diameter, fragrant. Very showy and one of the reasons the trees were so very popular in the day. Blooms for a very long time. Pollen bothers some people. Blooms best on old wood.



Fruit is a legume, 4-6" long, reddish-brown at maturity, They are brown, thin and twisted. But almost reddish late spring making one think the plant might be blooming again though a different color. Everyone of those seeds will germinate.





Bark is smooth, gray to silver-gray. Lots of bad crotch angles and included bark, making for branches coming down during the winds.



Misidentification:
Only likely A. baileyiana which is a smaller tree, more blue or silver colored and has smaller leaves with fewer lateral compound leaflets, see below.



Location: 
Again, these are everywhere in Santa Cruz except right up at the coast.

Sunday, March 27, 2011

Eucalyptus globulus - Blue Gum

Can there be a tree with a greater impact on our small county than the Blue Gum? Can you visualize the horizon without these huge trees?

This tree was going to bring so much to California. It did of course, but not all good. Imported from Australia for lumber mostly, it has taken over huge areas of our native landscapes, and many other species are still being planted today. For an interesting history click here. Also, be sure to look into Matt Ritter's book A Californian's Guide to the Trees among Us. He is the Eucalyptus expert. I attended a workshop of his at UCSC and he told us the first seed or trees were brought to Cordelia Junction in Fairfield by a ship captain and they are still there.

The trees lined the El Camino Real in Burlingame near where I grew up. They were huge then, messy but very impressive. The trunks look great when wet and they always smelled wonderful.

It is hard to image what our coast would look like without this tree. Actually, for some interesting pictures see the little white church in Soquel. This is the grove  leaving Capitola towards Aptos.




It is interesting to note that its not easy to fine a single specimen as they usually grow in groves. This is the same planting but on the walking trail. Very dense, nothing else grows there, which is why many consider this tree an invasive weed.




There are not many tress that can grow so close to the coast, or as far inland with seemingly the same success.  If you go up north into San Mateo County just across from Dunes Beach there is a grove that is wind stunted but thriving.

This specimen is located in Clubhouse Dr in RDM. I talked tot he owner about this one, he said he wanted to take it out but the bid was over $6K.




The blue gum grows very fast and will reach anywhere from 50-150' with a spread of about 35-50'. Very upright in habit, eventually forming a somewhat rounded crown. Huge upright lateral branches support lots of foliage. This one is on RDM blvd just past the railroad tracks heading towards the beach.




The foliage of Eucalyptus is of two forms, a juvenile form and an adult form. The juvenile form only shows up early or when the tree has been cut back hard or damaged by fire. It does not last long and is replaced by the typical form. Notice the leaves are opposite in this form, covered with a waxy bloom and sessile (no petiole). Generally ovate shaped.




The adult foliage is alternate, simple, sometimes lanceolate but generally falcate-shaped (sickle-like) 6-12" long x 1 -1.5" wide, leathery, pendulous off the branchlets, dark green or almost bluish green in color and similar on both surfaces, Margins are entire, tip pointed.




Flowers mostly in January here but bloom time can continue for a long time. Individual flowers are white, mostly solitary and quite showy. Look at the following image, the buds are 4 sided, and they have a "cap" that falls off. The "cap" is called the operculum, and is really the modified sepals and petals of the flower. (This operculum is often used to identify eucs as they are not easy to id.) The showy part of the flower are the stamens.




The fruit are large 4 sided woody capsules. They are produced in large quantities and are big enough to be a nuisance or a hazard. The capsules split open to release tiny seeds.




The branches and trunks are massive. They have beautiful exfoliating bark. The bark sheds in long strips that either get hung up in the branches or falls and you have to clean it up. Seems to shed all year. Notice how the bark twists up the trunk. The bark gets caught in the branch crotches in large trees and hangs for a long time.




There are a few examples of the compact cultivar 'Compacta', one in the shopping center along East Cliff Dr between 14th and 17th. Also along Highway 1 backing up to the old sash mill area. This one is in the Seacliff area.


There are not many pests of Eucalyptus, the Red Gum Lerp psyllid is one of the worst insect problems.

Mistaken identity? Not likely with the large sickle shaped leaves and the large single capsule.


Locations:
Is there anywhere they are not? I mentioned the grove along Park Dr to Capitola, and several in RDM.