Thursday, January 19, 2012


Brown garden snails (Cantareus aspersus/Cornu aspersum)  in a hibernaculum - Irvine, California.

Origin:  Latin word hibernare
Literal meaning:   winter residence
 Practical meaning:  a protected space that animals use as a shelter
for hybernation during prolonged periods of inclement weather.

Gardeners, what do you do when you see a population of snails in a hibernaculum?  

Monday, January 16, 2012

Brugmansia sanguinea: Toxic Angel

 Fig. 1  Brugmansia sanguinea 'Red Angel's Trumpet' Flower

Last year I got the chance to get really close to another angel's trumpet, the Brugmansia sanguinea.  The term sanguinea which is derived from the Latin word for blood (sanguis) describes the color of the corolla tube.  The color red distinguishes this plant from the species within the genus Brugmansia. 

These are the seven known species of Brugmansia according to the International Brugmansia and Datura SocietyBrugmansia arborea; Brugmansia aurea; Brugmansia insignis; Brugmansia sanguinea; Brugmansia suaveolens; Brugmansia versicolor; and Brugmansia vulcanicola.  They are native to South America along the Andes Mountains from Colombia to Chile. 

Fig. 2   Brugmansia sanguinea: The Corolla

Native environment. 
The flowers in the pictures here were all taken in Bogota, Colombia.  (My family visited one of the tourist attractions in Bogota - the  Mount Montserrate which can be reached by an aerial tramway or a funicular.) To give you an idea of environment there - Bogota is located somewhere along the equator with an elevation of about 10,300+ ft. above sea level.  The place is in the tropics but it feels like San Francisco, California.  Also, because it is located along the equator, the daylength is always the same throughout the year.  In other words the climate there is unexpectedly and consistently mild. 

Fig, 3    Brugmansia sanguinea - Pendant flowers

Fig. 4   Brugmansia sanguinea flowers are used as some sort of offering.

Toxic Angel.  The pendant flowers of the Brugmansia (Angel's Trumpet) are delightfully inviting but never forget that the plant is deadly. I have warned readers about the toxic contents of Brugmansia a while back.  I was shocked (not because of propriety but of safely) to see some pilgrims visiting the church at the top of  Montserrate, pick these flowers from the surrounding gardens and lay them down at the different stations of the cross (Fig.4).

Cursed Devil.   While Brugmansia is considered an angel (as in Angel's trumpet), she has a cousin who has fallen into the dark side.  Datura, aka Devil's Trumpet, is so closely related to Brugmansia that formerly they were classified under the same genus. That has changed.

These two relatives can be identified from each  other, firstly, by the position of their flowers.  Angel's trumpet hangs like pendant looking down to earth (Fig. 1) while Devil's Trumpet, looks up to the heavens as if asking forgiveness.  As the story goes, the devil was once an angel himself.  Secondly, Brugmansia is a woody plant (in a tree) while Datura is often an annual (herbaceous) and sometimes, depending on species and growing conditions,  a short-lived perennial.
It is well established that Datura, just like Brugmansia, is highly poisonous.  Careful handling of this plant is highly recommended. 

At 10,300+ ft elevation, Mount Montserrate has a tropical yet mild climate.

I've heard a European shepherd once say that it is alright to have wolves around his flock as long as he sees the wolves first before they see him.  The problem is when the wolves see him first - then it is too late.  Likewise, it better to know the dangers Brugmansia has before it tells you so.   

Monday, January 9, 2012

Mobile vs Immobile Nutrients

Fig. 1   Older leaves on celery turning yellow while the growing points in the center remain green.

The last time I looked there were seventeen known essential elements for plants.  Each element performs a specific function.  When conditions are at optimum levels we see a healthy plant, but when one or more element is deficient we see a "needy" plant.  To determine which of these various elements is lacking, one has to begin by understanding where the plant stores all its limited reserves.  Some elements are like cash - they can be used anywhere, while some are like gift cards - which can only be spent in specific stores.  Plant nutrients are either plant-mobile or plant-immobile.   Understanding these two characteristics is important because it helps gardeners interpret deficiency symptoms more accurately.

What are plant-mobile nutrients?

Plant-mobile nutrients are those that are capable of being translocated within the plant.  When a plant is deficient of these elements, the nutrient that is already within the plant will be transported to where it is needed most - the young tissues.  Deficiency symptoms of plant-mobile elements are observed on the older leaves first.  One example of a plant-mobile nutrient is nitrogen.  If nitrogen is deficient in a plant, older leaves would turn yellowish first while the newer leaves remain relatively green (Fig. 1). The plant directs the nutrient where it is most needed to prolong the life of the stressed plant.

Examples of plant mobile nutrients are nitrogen (N), phosphorous (P), and potassium (K).  Manganese and sulfur are moderately mobile

What are plant-immobile nutrients?
By now, the answer to this question is obvious.  Plant-immobile nutrients  cannot be translocated from older tissue to a new one due to the nature of the elements and sometimes other conditions.  In other words they are stuck where ever they landed the first time.   They have reached their destination.  Deficiency symptoms for these elements are observed in the young plant parts.  Calcium is an example of plant-immobile elements.  It plays an important role in cell expansion.  When calcium is deficient, the young shoots and flower buds exhibit the devastating effects.  If the condition is not corrected the shoots and bud get aborted eventually.

Examples of plant-immobile nutrients are:  Iron (Fe), Calcium (Ca), Manganese (Mn), Zinc (Zn), Copper (Cu), and Boron (B). 

Plant nutrients are like humans.  Some are always moving to where the activity is going on while others just settle where they landed the first time until they go back to the ground. 

Sunday, January 1, 2012

Adventitious Roots

Sedum reflexum 'Blue Spruce'

Profuse adventitious-rooting allows one plant to adapt under extremely dry conditons. 

May your roots be prevalent and deep.
So that you may prosper in all circumstances.
Happy New Year To All! 
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