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Carnegiea gigantea ‘Saguaro Cactus’


Habitat

The iconic Saguaro cactus, Carnegiea gigantea, occurs naturally in the Sonoran Desert.  This unique habitat, which is home to many other characteristic plants and animals, is shared by the United States (Arizona, California) and Mexico (Baja California, Sonora). The Saguaro Cactus ranges north to the edge of the Hualapai Mountains in Arizona and along the Colorado River in south-eastern California. The largest saguaro populations occur in the state of Sonora (Mexico) where its distribution reaches its southernmost point around Ciudad Obregón, the second-largest Sonoran city.

Ribbed Stem Trunk
Ribbed stem trunk of a Saguaro

Description

A member of the cactus family (Cactaceae), Carnegiea gigantea is a tall, tree-like cactus. It is columnar in form, the stem and branches tall and thin, like pillars, and grows up to 50 feet tall. The ribbed stem (trunk) can reach a diameter of 28 inches.  It is the largest columnar cactus native to the United States but is extremely slow-growing. It flowers once it has reached a height of about 6 feet.  The first branches, which grow out from the sides of the stem, only appear after it has reached a height of 16 feet and an age of 50 years.

Saguaro Cactus
RCDG ‘Saguaro Cactus’

The Saguaro stores water in its trunk and branches as an adaptation to its dry environment.  It has a deep anchoring taproot (the main root that goes straight down into the soil) up to 3 feet long and an extensive, shallow, lateral root system (roots that spread outward from the main taproot) that allows it to take up water quickly after the infrequent rains typical of the Sonoran Desert.

The trunk bears dense, strong, thick, spines up to 1.5 inches long on 12–30 prominent, vertical, ribs. The white flowers appear just below the top of the stem between April and June. They are 3-4 inches long and 1-2 inches in diameter. The flowers open during the night and are primarily pollinated by bats that feed on the abundant nectar.

However, they do remain open for some time in the morning when other animals, such as bees and birds, visit the flowers and further aid in pollination. The edible, red, fleshy fruits ripen from May to July and are 1-2 inches long and 1 inch in diameter.

Threats and conservation

Although not considered endangered, the Saguaro cactus is protected under the Arizona Native Plant Law. Illegal collecting of plants is a concern around cities, but the most significant impact on their populations is posed by urban development, especially near Phoenix and Tucson. Nowadays, however, developers have a duty to move or protect Saguaros that would otherwise be destroyed during building operations.

Native Americans

Saguaro fruits are highly prized among Native Americans. The delicious fruits have a juicy, red flesh with lots of tiny, black, nutty-tasting seeds.  They were a staple food of the Tohono O’odham and Pima Indians. The seeds are used as chicken food or ground into a flour to prepare a cake.

The internal ‘woody ribs’ of dead stems provided building materials and firewood, and were also used as splints for broken bones.

The Tohono O’odham organized their traditional calendar around the Saguaros annual fruiting cycle and considered the species to be so important that plants were regarded as fellow humans who should not be hurt.

Food for wildlife

The flowers, fruits and seeds of the saguaro are an important food source for Sonoran wildlife, such as the collared peccary, long-nosed bats, rodents, western white-winged doves, woodpeckers and insects.  Saguaros provide nesting habitats for birds and small mammals.  When Gila woodpeckers and gilded flickers dig their nests into the plant’s flesh it produces a hard callus lining to the cavity that seals it off from the surrounding living tissue.  Once a saguaro has died and the soft flesh has rotted away, the hard lining of these bird nesting cavities remains intact, forming curious looking container-like structures that stick out among the remains of the dead plant.

SaguaroBoot
Saguaro Boot

These so-called ‘Saguaro Boots’ were used as containers by North American Indians.

About Aloes

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Aloe ssp.

 Aloes are some of the most striking plants in the dry landscapes of Africa, there are over 500 species of flowering succulent plants.  Aloes come in a variety of growth forms, from small to tall single-stemmed or branched trees.  The leaves of the aloe are lance or sword-shaped in outline and boat-shaped in cross-section.  Most Aloe species have a rosette with large and thick fleshy leaves, the flowers are tubular and are frequently yellow, orange, pink and red.

Aloes are xerophytes with structural and physiological adaptations for survival.  The majority of Aloe species are found in arid or semi-arid regions.  They occur in a wide range of habitats, including dry forests, open woodland, grassland, bare rock surfaces and cliff faces.  Some grow near the coast, almost at sea level, and only a few occur at altitudes up to 10,000 feet.

DISTRIBUTION OF ALOES

The genus of Aloe occurs throughout most of Africa south of the Sahara Desert, in the Arabian Peninsula, on Madagascar and smaller islands in the Indian Ocean.  The most widespread of the aloes is Aloe myriacantha, which is found in northern Kenya and down to the southeastern parts of the Republic of South Africa in Eastern Cape Province.

USES OF ALOES

One of the most frequent and widespread use of aloes is as an ornamental plant, some artificial hybrids have been created for this purpose.  Many species are used for landscaping in tropical and sub-tropical climates and as general landscapes and container gardens in areas with low or erratic rainfall.  Many different soil types support aloes in the wild, though most species are tolerant of  any kind of soil in cultivation.  Some arborescent species are used as street trees in Africa i.e., Aloe bainesii and A. dichotoma.  Smaller growing species are best suited for an indoor windowsill plant such as Aloe aristata.  

The second most frequent use of aloes is as an medicinal herb.  Aloes have been collected for their medicinal qualities since classic times and as ornamentals for several hundred years. aloe species contain compounds that are of medicinal value, and traditional healers have used the plants in herbal medicine for centuries.  In medicinal history Aloe vera has been cultivated around the tropics and sub-tropics as a medicinal plant for over 2500 years, this aloe species has been used for treating burns, rashes, acne, psoriases, rosacea,  athletes foot and  insect bits.

ALOE CHARACTERISTICS 

Most aloe species are leaf succulent xerophytes, having conspicuously fleshy leaves.  Only a few grass aloes such as Aloe myriacantha have leaves that are small and not fleshy.  Aloe leaves are simple usually with marginal teeth and in some species with teeth or prickles on the leaf surface.  Leaves may be rosulate or dispersed along the stem.  Many rosulate species are described as acaulescent which means that the stem is so short that only the leaf rosette can be seen as the plant.

Jacaranda mimosifolia

J. mimosifolia
J. mimosifolia

Jacaranda trees are tropical beauties with clusters of fragrant, purple, trumpet-shaped blooms which are 1-1/2 inch long curved with inner white throats.

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Trumpet shaped bloom with inner white throat

 

The heaviest-flowering happens when grown in full sun, it can tolerate light shade and will grow quickly. Jacarandas often have an  open, irregular and oval headed growth habit; its stout trunk, gray rectangular flaked bark and alternately arranged finely divided bipinnately compound leaves that are at least a foot long and composed of 1/2 inch long narrow elliptical leaflets that give the tree a delicate fernlike appearance.

DSC_0008
1/2 inch long narrow elliptical leaflets

Jacarandas thrive in sandy, well-drained soils but should be watered during dry periods.  Plant in full sun with occasional deep summer watering and preferably in a soil that drains well.

Jacarandas will often survive in heavier soils but growth is slow and sometimes stunted; flowers and leaves may cause a lot of litter when they drop. 

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Rice Canyon Jacarandas

Jacaranda trees tend to form vertical suckers when pruned that distort the shape of the tree.  If pruning, only remove broken or diseased branches; so avoid pruning your Jacaranda.

Scientific Name: Jacaranda mimosifolia

Common Name: Jacaranda

Family Name: Bignoniaceae                        Origin: Brazil                 

Plant Type: Tree                                                 Leaf Type: deciduous

Density: open                                                      Texture: fine                

Height ft. 25′-40′                                              Width ft. 15′-30′  

Form: irregular, oval                                          Growth Rate: fast                 

Leaf Type: bipinnately compound, odd-pinnately compound    

Leaf Arrangement: alternante                  

Leaf Shape: obovate; rhomboid                  Leaf Size: 2″ 

Leaflet Size:                                                          Leaf Margin: entire    

Leaf Color: green                                                Leaf Fragrance: yes   

Flower Showy: yes                                            Flower Cluster Type: panicle 

Flower Season: Spring – Summer               Cut Flower: no     

Flower Fragrance: yes    

Flower Color: purple, blue, lavender        Fruit Type: round, pod-like  

Fruit Size: 1-3″                                                    Fruit Edible: no 

Fruit Color: brown                                             Fruit Showy: yes             

Bark Color: gray-brown                                 Root Type: surface roots                

USES: : large parking lot islands, wide lawns, shade trees, specimen tree, residential street tree, mass planting.                             

Sun Exposure: full sun                                    Climate:  zones 12-24

Water: water during dry periods, deep and infrequent.    

Pruning: no   

Propagation: cuttings, grafting, seeds                

COMMENTS: Pruning Jacarandas will spoil their good looks, and the tree’s shape. When you prune a Jacaranda it then sends up vertical shoots. The normal shape for a Jacaranda is that of an elegant umbrella, and the appearance of vertical branches ruins its good looks. 

Jacarandas are well-suited for cooling patios, but should not be used near pools due to the abundant leaf and flower drop.

Hesperaloe parviflora ‘Red Yucca’

Red Yucca
Red Yucca spikes of reddish-pink flowers

Red Yucca is  stemless clumping, arching succulent which has spreading grass-like foliage 3-6 feet tall.  The leathery long, narrow blue-green leaves have deep grooves and white fraying fibers along the margins.  Clumps can spread slowly up to 4 feet in width and in mid-summer the clusters of rose-pink flowers are borne on tall red flower stalks which are 6 feet in length that arch up and outward.  Flowers open from the bottom up and are attractive to hummingbirds. Individual rosettes only flower once and are replaced by younger ones.  Red Yucca is drought tolerant and does best in full sun or partial shade and likes well-drained soils. It is a good plant for desert and succulent gardens, planted in masses or used in pots.   Occasional irrigation is recommended in summer to encourage flowering but do not over water.

 

Scientific Name: Hesperaloe parviflora

Common Name: Red Yucca

 Family Name: Agavaceae                                                                                Origin: Chihuahuan desert of west Texas east and south into central and South Texas and northeastern Mexico around Coahuila.

Plant Type: perennial                                               

Leaf Cover:   evergreen                                   Density: open

Texture: medium                                                Height ft. 2’-6’

Width ft. 4’                                                            Form: clumping  

Growth Rate: slow-moderate                      Leaf Type: simple 

Leaf Arrangement: basal                              Leaf Shape: lanceolate

Leaf Size: 3’-4’                                                     Leaf Margin: develops threads

Leaf Tip:   acute                                                   Leaf Color: gray-green  

Flower Sex:   Hermaphroditic                      Flower Showy:   showy   

Flower Size: 1.25”                                          

Flower Cluster Size: 5’                                                                    

Flower Season: spring-summer                                                                   

Flower Color: pink, red, yellow        

Fruit Type: cap                                                    Fruit Size: 1 ¼”     

Fruit Edible: no                                                   Fruit Color: brown  

Fruit Showy: no                                                  Root Type: moderate 

Branching: basal clump                 

USES: background, container plant, flower effect, foliage effect, low maintenance, mass planting, rock garden, specimen plant, great choice for pool landscapes.                        

Soil Texture:  well drained                           Soil pH: alkaline  

Soil Moisture: dry to moist                         Sun Exposure: full sun   

Hardiness:  hardy 10 or less                       Climate: heat, drought, aridity

Water: sporadic                                                Fertilizer:  never                    

Pruning: remove old foliage        

Propagation: division or seed                                        

COMMENTS: Individual flowers are bell shaped.   Fruit contains flat black seeds

Penstemon parryi ‘Parry’s Penstemon’

Parry’s Penstemon is a desert wildflower native to Southern Arizona, Northern Mexico, and the Sonoran Desert.  This perennial blooms late February through early May.  In its native habitat plants flower in their second year; if cultivated flowers will usually bloom in the first year.

Parry's Penstemon
Parry’s Penstemon

Leaves are bluish-green and at the base emerge the flower stalks, which are 1 to 3 feet in height and topped with pink deep-throated flowers attracting lots of hummingbirds, bees, butterflies and birds.

Penstemon hot pink blooms
Penstemon hot pink blooms

This lowland desert species thrives in full sun to partial shade and can survive on average rainfall, but not prolonged drought.  Plants are self-fertile and produce copious amounts of seeds.  With good rains seedlings will germinate, grow and bloom within a few months.  Division is possible, but seeds are the primary means of propagation.  

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Scientific name: Penstemon parryi    

Common name: Parry’s Penstemon, Parry’s Beardtongue, Desert Penstemon

Family name: Scrophulariaceae

Origin: Southern Arizona, Northern Mexico, and the Sonoran Desert

Plant type: Perennial                          Leaf cover: Evergreen                              

Density: open                                         Texture: fine

Height ft.  2-4′                                        Width ft. 6″            

Form: upright                                          Growth Rate: fast                

Leaf Type: lanceolate                          Leaf Arrangement: rosette 

Leaf Shape: arrow shaped                Leaf Size: 6″                    

Leaf Color: bluish-green                    Leaf Fragrance: none     

Flower Sex: Hermaphroditic           Flower Showy: showy                             

Flower Cluster Type: wide funnel                

Flower Size: 3/4″                                  

Flower Season: Late February to early May  

Cut Flower: no                                      

Flower Fragrance: none                 

Flower Color: pink                            

USES: alkali tolerant,  background effect, border effect, flower effect, foliage effect, hillside, low maintenance, rock garden.

Comments: Removal of flowering stalks just as seed is forming will stimulate more blooms and prolonged life of plant.  Irrigating in the summer will enhance next years blooms.

Chula Vista Open Space