Arboretum Images 7b

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    Palms        Bamboos        Agaves        Cactus        Conifers1        Conifers2        Legumes1        Legumes2        Figs (Ficus)  
    Trees1        Trees2        Trees3        Shrubs1        Shrubs2        Shrubs3        Wildflowers  
Palomar College Arboretum Images 7: Shrubs #2
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Protea Family (Proteaceae)

Left: Banksia media native to the coast of southwestern Australia. This species has conelike clusters of seed-bearing follicles that open during the heat of a fire. Right: Another coastal banksia (Banksia integrifolia) native to New South Wales on the southeastern coast of Australia. The latter plant was photographed at the San Diego Wild Animal Park's Protea Garden. It also has a conelike follicle cluster that opens by fire. Like our local shrubs of the coastal sage scrub and chaparral, some Australian banksias develop a woody, subterranaean lignotuber that resprouts after fire. Although they are morphologically very different, several California pines have serotinous seed cones that open by fire. These are similar fire adaptations in unrelated plants on different continents that are subject to periods of prolonged drought and periodic wild fires.

  Banksia Seed Cone Opened In Oven  
Adaptations Of Wild Plants To Fire

Firewheel tree (Stenocarpus sinuatus), a striking flowering tree native to northeastern Australia. The peculiar flowers are produced on long red stalks that are arranged like the spokes of a wheel.

Rose cone flower (Isopogon formosus), another Australian shrub in the protea family.

Yellow cone flower (Isopogon anemonifolius) native to New South Wales.

Leucospermum reflexum (var. luteum) native to South Africa.


Legume Family (Fabaceae)

Hoary pea (Tephrosia grandiflora), a small leguminous shrub native to South Africa. Flattened pods and pairs of triangular stipules at the leaf bases are characteristic of this species. The name "hoary" refers to the appressed, silky pubescence on the stems and undersides of leaves. The dark red papilionaceous flowers resemble those of a sweet pea. This perennial shrub remained unidentified in the Arboretum for many years. Special thanks to Steve Brigham of Buena Creek Gardens in San Marcos for finally identifying this interesting legume.


Barberry Family (Berberidaceae)

Holly-leaf barberry (Berberis aquifolium). This spiny-leaved shrub is also placed in the genus Mahonia by some authorities. In Oregon, it is referred to as "Oregon grape." According to the Jepson Manual of California Plants (1996), there are three varieties of Oregon grape native to California.

Darwin's barberry (Berberis darwinii). This spiny-leaved shrub is native to southern Chile and southwestern Argintina. It was discovered by Charles Darwin in 1835 on his famous voyage of the HMS Beagle, and named in his honor.


Soapberry Family (Sapindaceae)

Texas buckeye (Ungnadia speciosa), a member of the soapberry family (Sapindaceae). The "nuts" of these species are actually hard-shelled seeds produced in dehiscent capsules that split open at maturity. Right: A colorful necklace made from the bright red seeds of mescal bean (Sophora secundiflora) and shiny black seeds of Texas buckeye.


Rose Family (Rosaceae)

California holly (Heteromeles arbutifolia), a native shrub in the hills east of Palomar College. It is abundant in the chaparral throughout coastal southern California. In fact, the city of Hollywood is named after this shrub. The generic name Heteromeles means "different apple" because the fruit resembles a miniature pome.

California holly (Heteromeles arbutifolia). The specific epithet "arbutifolia" refers to the similarity of the leaves to species of Arbutus, such as the strawberry tree Arbutus unedo. The latter tree belongs to the heath family (Ericaceae). California holly is also called toyon. The small fruits are structurally the same as apples. They are mostly composed of hypanthium tissue surrounding a seed-bearing core which is the actual ovary.

  Fruit Terminology Page: Fruits With A Fleshy Pericarp  
See Leaves & Fruit Of Strawberry Tree In Heath Family

California holly (Heteromeles arbutifolia). The fruit is technically called a pome because the seed-bearing ovary (core) is surrounded by hypanthium tissue. Like an apple, the edible fleshy part is mostly hypanthium rather than pericarp tissue. And like an apple, it oxidizes quickly resulting in the brownish color. It even tastes like an apple. The following link illustrates its similarity to an apple.

  Comparison Of California Holly Fruit With An Apple  


Chocolate Family (Sterculiaceae)

Some references place the genus Dombeya within the Sterculiaceae, Byttneriaceae or
Malvaceae.  These three families, plus the Tiliaceae and Bombacaceae, are obviously
closely related phylogenetically and are typically placed in the large order Malvales.

Pink ball (Dombeya wallichii), a beautiful species native to eastern Africa. A cultivated hybrid between D. wallichii and the South African D. burgessiae is planted nearby. It is named D. x cayeuxii. Both specimens are very similar in appearance.

Strawberry snowball tree (Dombeya cacuminum), a species native to Madagascar.

The strawberry snowball tree (Dombeya cacuminum), is unquestionably one of the most beautiful flowering trees in the Palomar College Arboretum.


Buckthorn Family (Rhamnaceae)

This beautiful native California shrub called "blue blossom" was originally identified in the Arboretum as Ceanothus griseus; however, it is very close to the description for C. thyrsiflorus in the Jepson Flora of California (1996). An older synonym for this species is C. thysiflorus var. griseus.

Dorsal view of an adult ceanothus silk moth (Hyalophora euryalus) sitting on the native California shrub called blue lilac (Ceanothus thyrsiflorus). This beautiful moth is native to the local hillsides of chaparral above California State University San Marcos.

  More Images Of The Ceanothus Silk Moth