Tree of the Week: The dependable Laurel-Leaf Cocculus

 

Laurel-Leaf Cocculus – Cocculus laurifolius

Not many trees grow equally well in sun or shade. But the Laurel-Leaf Cocculus, a native of South Japan and the Himalayas, goes its own way, regardless of its surroundings.

This dependable plant looks fresh and shiny green, with a dark and dense interior. The leaves have a unique three-vein structure, with one prominent vein in the middle and the other two close to the leaf edges. Once shaped, it is a rather low-maintenance tree that is used as a screening, accent or entrance plant. It is also known as Platter-Leaf and Laurel-Leaf Snailseed and is a member of the Menispermaceae or Moonseed family. Alkaloids isolated from the leaves were used in Indian folk medicine. The cut-foliage industry uses the leaves to add green to bouquets.

The evergreen cocculus starts out slowly but gradually becomes a moderately fast-growing shrub or arching, umbrella-shaped, multi-trunked small tree, to 15 to 25 feet tall and wide, depending on how it is pruned. The vining branches are also easily espaliered to create a flat green screen. The bark is smooth and brown. Alternate, simple, pointed, leathery, shiny, elliptical leaves are 6-plus inches long. Insignificant, small greenish white flowers are followed by small, blackberry-like fruit. The tree is moderately drought-resistant but prefers moderate to regular water. It is not demanding about soil, has non-invasive roots and is little bothered by pests and insects.

-- Pieter Severynen

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Photo: Marty Rose

Tree of the Week: Ohio buckeyes? This one's a native of California

California buckeye -- Aesculus californica

The California buckeye is the wild and graceful relative of the stately horse chestnut tree with the magnificent red or white upright flower spikes and the big hand-shaped leaves. This California native, whose seeds resemble the big brown eyes of bucks (male deer), grows at lower elevations throughout our coastal ranges and the Sierra Nevada.

All parts of the plant are more or less poisonous. Local Pomo, Yana and Luiseno Indians used ground seeds to stun and catch fish. However, after roasting, grinding and leaching, the seeds are edible. Flower nectar may be toxic to honeybees, but attracts hummingbirds and butterflies. Carl Linnaeus, the Swedish botanist, named the genus after the Latin name for an oak tree bearing edible acorns.

The deciduous California buckeye grows at a slow to moderate pace to a long-lived, often multi-trunked, open, 15-to-25-foot round-head, vase or umbrella shape. The bark is thin and gray and becomes mottled whitish on older trees. Twigs are smooth and reddish brown when young. Opposite leaves are palmately compound, consisting of five to seven 4-to-6-inch-long, 1 1/2-to-2-inch-wide leaflets joined on a central stalk. Small, sweetly fragrant, white or pink flowers are borne on 4-to-8-inch-long upright plumes that grab attention. Pear-shaped, leathery capsule-like fruits contain one, sometimes two, 1-to-2-inch-long shiny, orange-brown seeds.   

The tree is drought-resistant once established, but in the garden looks better with some summer water. Without extra water it starts dropping its leaves in midsummer and may stand bare for two seasons. A low-maintenance tree that seldom needs pruning, it likes partial shade to full sun and is not fussy about soil. It makes interesting bonsai material.

Forty years ago the California buckeye tree pictured above, located near Strawberry Creek at the UC Berkeley campus, seemed close to death. It was hollow, ghostlike and literally a shell of its former huge self. On a recent visit to the campus I wanted to see if any trace of the tree remained. Not only was it still there, but it was actually in much better shape, no doubt thanks to some special care and attention. Even with a hollow trunk full of holes, it had grown new branches and a healthy central core, while fruit hung from its branches.

-- Pieter Severynen

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Photo: Pieter Severynen

Tree of the Week: Use the African sumac for shade or perhaps to make beer

African Sumac -- Rhus lancea

Some trees are valuable, not for one spectacular characteristic, but because they are so utterly reliable doing the mundane job we expect of them. The African sumac, also called Searsia lancea,  is a case in point. It will never win an award for great flower display, intriguing smell, striking silhouette or luscious leaves. But when we want a small to medium size, round-headed evergreen tree that can be depended upon to cast dense shade in a parking lot, or to dependably line the street, and not be fussy about its surroundings, while taking smog and indifferent pruning for granted, then we can do a lot worse than plant the African sumac.

It is native to the central and Cape regions of South Africa, where it is called Karee and does especially well along stream banks. After initial planting in the Tucson area it was found to be very adaptable to most areas in the West. According to one report it actually started naturalizing in the Tucson area. We always become a little suspicious when trees do that, because we don’t want them to get out of hand in their new surroundings, but it is not listed as an invasive plant in California.

The evergreen African sumac grows at a slow to moderate rate to 20 to 30 feet tall and wide. It naturally assumes a graceful, open, spreading, multi-stem habit, reminiscent of an olive. Pruning of basal suckers will keep it a single trunk tree. On older trees fissures in the dark gray trunk reveal an orange color beneath. Young twigs are reddish in color. Leaves are divided into three willow-like, smooth-margined leaflets, 3 to 5 inches long, dark green but somewhat paler underneath. The tree drops some leaves in summer. Small whitish green flowers smell slightly sweet; pollen is allergenic; clusters of flowers on female trees develop into small pea-size fruit containing red or black seeds with papery coats. In its homeland the fruit was used to make beer. The tree loves full sun and is drought-resistant once established. It is not particular as to soil, but susceptible to Texas root rot.

The genus Rhus occurs worldwide. It is part of the Anacardiaceae family, which also houses such interesting members as mangoes, cashews and poison oak.  
 
--Peter Severynen

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Photo: Peter Severynen

Tree of the Week: Flame Tree -- Brachychiton acerifolius

The Flame Tree is spectacular in its midsummer bloom when a cloud of bright red flowers hangs over the leafless branches.

That is, in the years that everything goes right, when all branches bloom at the same time and have also lost their leaves.

Of the Kurrajongs, Australia’s term for its Brachychiton trees, the deciduous ones are sometimes a little undecided as to when to go leafless and how much to bloom. The (Illawara) Flame Tree, a member of the Sterculia family that is also known as Sterculia acerifolia, is native to escarpments of the Australian East Coast rain forest. In the Southland, it manages to get by with little to moderate water. The tree has a rather relaxed attitude about the shape of its leaves, which may resemble maple leaves (acerifolius), and have multiple lobes, or no lobes at all. All Kurrajongs display equal ease about hybridizing with each other. The tree may take seven to 10 years to bloom, though grafted varieties bloom a lot quicker. It is medium frost tender (CA zones 15-24).

Brachychitons tend to form strong central leaders, but occasionally a competing second trunk appears that should be pruned. The Flame Tree is briefly deciduous in summer and grows at a moderate rate to a pyramidal 60 feet tall by 30 feet wide. Green to gray smooth bark clothes the sturdy trunk. Bright shiny green leaves, up to 12" long and 10" wide, densely cover the tree, and the bloom is best after a dry winter. Clusters of small ¾-inch tubular red or orange flowers appear in late spring or summer, when the tree is usually leafless. After flowering, dry, woody, 4"-long brown or black canoe shape fruits develop that contain seeds and are covered with small bristles (brachy-chiton means short tunic). The tree loves full sun, will take a variety of soils, lawn watering and dry sites and is bothered by few pests or diseases.

The following holds true for all trees: a strong central leader may become a liability when the tree is planted close to power lines (as in the photograph above) and the power company wants to maintain separation. In that case, the branches on the side of and close to the power lines may be removed, or, if the trunk is directly underneath the lines, the main stem can be cut at a lateral, so that side branches will grow and form a tunnel around the lines. A tunneled tree may look better than an unbalanced one-sided one.

--Pieter Severynen

Thoughts? Comments?

Photo: Pieter Severynen

Tree of the Week: A native California pine by the name of Jeffrey

The Jeffrey Pine -- Pinus jeffreyi
 
Most trees discussed here are widely distributed in the Los Angeles area. The Jeffrey pine is an exception: it is mainly confined to the mountains (Sunset Garden Book Zones 14-19), and while it occasionally grows at lower elevations, it likes to be far above 1600 feet.

The Scottish botanist and plant hunter John Jeffrey discovered this native Californian near Mount Shasta in 1852. Originally it was thought to be a variety of the Ponderosa pine, a well-known timber pine, but later it became clear that, while related, it is a separate species. It will grow on more extreme sites than the Ponderosa pine, the needles are less bright green, the heavier cones lack spines, the bark is more reddish brown and, due to the unusual composition of its resin, it smells distinctly of vanilla (some say pineapple), which the Ponderosa’s bark does not.

The Jeffrey pine grows moderately fast to a stately, rather open, 60 to 120 feet tall, 20 to 25 feet wide and 400- to 500-year-old tree, but on excellent soil and with high precipitation it can reach over 170 feet tall with a 6-foot trunk diameter. Supported by a deep taproot and a strong root system, it will endure harsh sites, infertile soils, drought and freezing cold. Almost all the wood produced goes into the straight and thick trunk; the horizontal branches are small in diameter while the scaly bark is silvery to purplish-reddish brown. The soft-looking, 5- to 10-inch-long, blue-green needles are borne in bunches of threes. Inconspicuous flowers appear every two to eight years in June and July on older trees; the female ones develop the next year into 6- to 12-inch-long, oval, reddish-brown, almost stalkless cones with inward curving spiny tips. Seeds are edible.

The Jeffrey pine loves the company but not the competition of other trees yet is intolerant of shade. It is moderately resistant to fire, and may suffer some from several diseases and pests such as the witches-broom-like dwarf mistletoe. In its habitats it supports a multitude of birds, squirrels and other animals. 

The tree is often seen in bonsai displays. Its pitch was distilled for turpentine at an earlier time or used for medicinal purposes. Commercially there is no distinction between Ponderosa and Jeffrey pine.

--Pieter Severynen

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Photo: Pieter Severynen

Tree of the Week: An (almost) evergreen ash from the olive family? It's a shamel

Shamel ash – Fraxinus uhdei

Dozens of different species of ash trees grow around the world, all part of the olive family. Fairly fast growing, they are used for street, shade and lawn trees; their hard, high-strength wood provides tool handles, baseball bats, veneer, bodies for musical instruments and firewood. Some species exude a sugary substance, which the ancient Greeks called meli (honey) and harvested commercially.

Ash trees became newsworthy when the emerald ash borer, a wood-boring beetle accidentally introduced in this country from east Asia around 1998, started threatening billions of ash trees nationwide.

The shamel or tropical ash is one of the few (semi)evergreen ashes; this Mexican native is a favorite in Southern California. The tree was also introduced in Hawaii but started escaping in the wild. Here in our drier climate it is better behaved.

The shamel ash grows fast to eventually reach 70 or 80 feet. Initially upright and narrow, in later age it may widen to 60 feet. A slower growing variety is available. (As always, these measurements assume that tree trimmers don’t impose their own will on the shape of the tree).

The upright trunk is covered in gray bark, split in small parallel pieces. The tree is notorious for developing V-shaped crotches. These narrow angles of attachment are found on main upright branches that often compete with the main trunk in size. They are weakly attached to the trunk, prone to break off and very difficult to prune. It is much easier to get rid of them when they are little. Lateral branches are opposite, a family trait.

Foliage is luxuriant green, and like most ashes, opposite and pinnately (bird feather-like) compound. The five to nine glossy leaflets, finely toothed at the edge, are about 4 inches long.

Some people are allergic to the flowers. Female trees carry barely noticeable clusters of small green flowers, which in summer develop into samaras, dry fruits with brown papery wings on one or both sides, which spiral down as they fall upon ripening. The accompanying picture shows the load of samaras one tree can carry. The tree is drought-resistant but does much better with regular water; it loves a lawn location but eventually the shallow roots may start lifting nearby pavement. The tree is not particular as to soil but wants full sun. The shamel ash is a reliable tree as long as it receives structural pruning when young it and it gets room to spread out when old.
  
The name ash is used to designate species of the genus Fraxinus, but also those of Sorbus (mountain ash), while in Australia some Eucalyptus are also called ash.

-- Pieter Severynen

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Photo: Pieter Severynen

Tree of the Week: A palm with a ponytail and a canteen

 

The ponytail palm -- Nolina (Beaucarnea) recurvata

Delightful and unexpected, a mature ponytail palm looks like it was drawn by Dr. Seuss. Its caudex, or swollen base, is a big onion-like bulb up to 12 feet across, but it might take a lifetime to get to that size. The bulb stores water and allows this bizarre succulent to go dry for long periods of time. The squat, occasionally branched, bare trunk or trunks curve upward in curious lines, while tufts of up to 6 feet long but only 1-inch wide, arching and drooping leaves are clustered together in sloppy umbrellas. Stalks of creamy white flowers jut out above the leaves at odd angles.

Strictly speaking, this evergreen perennial member of the Agave family does not produce the wood that makes it qualify as a tree, and it is also not a palm. It does attain tree-like size if you wait a very long time, for it is a very slow grower. It may be planted in ground outside or kept for decades as an indoor or outdoor potted plant. Should you forget to water a well-watered one for a month or so, either in the container or in the ground, no big deal: it will probably live happily ever after. In fact, it is easier to over-water this plant than to underwater. No two plants are alike and it makes a most unusual gift.

The ponytail palm may grow to 12 to 15 feet tall (up to 30 feet if of great age, but if in a container more likely 6 to 8 feet) and 10 to 12 feet wide. Thick trunk and gray bark resemble the leg and skin of an elephant; the caudex has the same skin, but will become many feet across. Tough, strap-like leaves are carried in one or more rosettes; on the commonly sold variety intermedia, the leaves are 3 feet long. Flower stalks hang on for a long time; eventually seeds develop, but only on female plants since they are dioecious ("two houses," meaning separate male and female plants). The ponytail palm needs full sun or light shade, will take many types of soil but prefers the lighter ones; it cannot live with standing water, tolerates light frost and is rather pest-free (the few that may occur when kept as a houseplant are easily taken care of). 

Several Nolina species populate the southwestern U.S., but the N. recurvata is a native of the Southeastern Mexican desert. The botanical name honors C.P. Nolin, an 18th-century French horticulturalist. Common names include bottle palm and elephant-foot tree. The genus used to be known as Beaucarnea, but under international nomenclature rules the oldest given scientific name prevails.

-- Peter Severynen

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Photo: Peter Severynen

Tree of the Week: Why the evergreen primose earned the name 'cow itch tree'

 

The Primrose Tree -- Lagunaria patersonii

Norfolk Island, which brought us the Norfolk Island Pine, shares the birthright to the Primrose Tree with Australia.

The first thing you notice about this tree are the gray leaves, about the shade of olive tree leaves. This will never be a green-leafed tree. The second thing is that you may not notice the tree all year until it is full bloom. Then you may suddenly wonder where the two-inch-wide pink or purple flowers with the long protruding yellow stamens, closely resembling those of the related hibiscus, came from.

The genus was named for Andres Laguna, the 15th century botanist, and the species for the 18th century British naturalist William Patterson. Those names at least are a lot better than the unfortunate name of "cow itch tree" it acquired, bastardized from the Indian "cowage," and in addition applying to a different plant, Mincuna imbricata. But it is true that fine hairs in the seed capsules may irritate, so sensitive people, small children and pets should not handle the seed pods.

In youth the evergreen primrose tree grows fairly fast and narrow, to 25-plus feet, but in later life it may get broad-topped. The bark is smooth and gray. The leaves are 2 to 4 inches long and oval. They are olive green above and gray green below, and densely cover the tree. Pink or purple hibiscus-like flowers make the tree stand out in bloom; they fade to almost white. Royal Purple has purple flowers.

Flower arrangers love the brown seed capsules. These hang on for a long time, then split into five sections, revealing bright brown or orange seeds and the itchy hairs.

The tree will take drought, a variety of soils, heat, open wind, salt spray and a little frost. The bloom is best when still somewhat subject to coastal conditions. I have never seen the tree become very popular, but I have never seen it go out of style, either.

--Peter Severynen

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Photo credit: Peter Severynen

Tree of the Week: Flaxleaf paperbark

The flaxleaf paperbark -- Melaleuca linariifolia

More than 100 melaleucas originate in Australia. All have narrow or needle-like leaves, bottle-brush like flower clusters and woody seed capsules. Some have contorted branches and thick papery bark that peels off in layers. Most are easy to grow.
 
The flaxleaf paperbark tree, also called snow-in-summer for its sometimes abundant cover of white fluffy flower clusters, comes from Eastern Australia’s New South Wales and Southern Queensland, where it grows near watercourses or swamps. Melas (black) and leukos (white) refer to the appearance of black fire marks on a white trunk. Linariifolia means with leaves like the (snapdragon-like) toadflax. In naming, botanists refer to what they already know.

A quick-growing, small, dense tree to 30 feet tall by 20 feet wide and umbrellalike in shape, the flaxleaf has a soft and spongy bark that peels off in strips. Young branches are soft and slender. The 1½-inch bluish-green leaves feel stiff but look soft. Flowering can be profuse. The small, white, slightly perfumed flowers are followed by woody seed capsules. The tree takes drought and poor soil, but also periodic inundation. It makes a good screen and shade tree and has no obvious pests.

--Peter Severynen

Thoughts? Comments?

Photo: Peter Severynen

Tree of the Week: The monkey puzzle tree

The monkey puzzle tree -- Araucaria araucana

Depending on your point of view, the national tree of Chile has a distinctive open symmetrical silhouette or it is a bizarre pyramidal evergreen with snaking branches and sharp-pointed, stiff leaves. Found in Chile in the 1780s, this native of Chile and Argentina, inhabiting the lower slopes of the South Central Andes Mountains, was named for the local Araucana people. Since there are no monkeys in its native range, the common name is only theoretical.

The tree is sometimes planted as a novelty in a large landscape area, but its habit of dropping 10-to-15-pound cones makes it inadvisable to linger nearby. The monkey puzzle tree may live to a ripe old age, reputedly up to 1,000 years old, but conversion of habitat is threatening its existence in parts of its original range.

Slow-growing in youth, the monkey puzzle tree eventually reaches 70 to 90 feet tall and 30-feet wide. The gray-barked trunk is straight; heavy branches droop down, but sweep upward at the end. Shiny and sharp leaves are less than 2 inches long and may last for 10 years. Male and female cones, produced when the tree is 30 to 40 years old, usually are borne on separate trees. Seed production in the 6-to-12-inches long, 3-to-6-inches-wide female cones is heavy and the seeds are edible.

The tree prefers regular water but is somewhat drought-resistant. It likes full sun and tolerates almost any well-drained soil. It will take frost and snow, needs little or no pruning and is little affected by pests or diseases.

Usually an oddity, the tree does occur in the Los Angeles area but the accompanying picture was taken on a recent trip in the Netherlands. The owners of this particular tree may not have realized its ultimate size or fruit disposal technique.

--Peter Severynen

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Photo: Peter Severynen