Acineta chrysantha

Acineta is a genus of orchids that is part of the Stanhopeinae, and is native from Mexico to South America.  They are large plants with big pseudobulbs that have 2-4 leaves per pseudobulb.  The inflorescences can be 11.8 to 27.5 inches (30 to 70 cm) long.  This orchid is native to moist cloud forests of Costa Rica, El Salvador, Guatemala, and Panama. It is found at elevations from 4,265 feet (1,300 m), and is a warm to cool growing orchid.  I grow this species outside with Stanhopea on the north facing side of my house in partial shade.



Acineta chrysantha inflorescence

The flowers of this species are waxy and up to 2.5 inches (6 cm) wide.  They open partially and are carried on long inflorescences to 27.5 inches (70 cm) long with up to 30 flowers.  The flowers have a base color of deep or golden yellow with reddish spots on the petals and sepals.  The labellum has large deep red spots and splotches.  The column, in contrast, is ivory white and minutely hairy at the base.  The fragrance of these orchids is rather complex, but ranges more toward a ginger or ginger beer fragrance.  I have heard of this species having a vanilla fragrance, but my variety has a more complex and intense scent.



Acineta chrysantha flower

This orchid has always bloomed for me in late summer and early fall.  The flowers last much longer than most Stanhopea, from two weeks, sometimes up to three weeks if the weather is cool.  The plant requires a cool and semi-dry rest period in early winter to induce blooms.  The first inflorescences grow out of the basket in July and take about 2-3 months to mature and open.

Stanhopea oculata (gold form)

Stanhopea oculata (gold form) inflorescence

This is a different form of Stanhopea oculata that I purchased because it has golden yellow flowers that are more intense than the other forms of the species.  The upper hypochile has a deep golden yellow color and the sepals and petals are a light to golden yellow color. This form also blooms at a later time (late summer/early fall)  than the pale cream to yellow colored form, and it only has two large eyespots on the upper hypochile rather than the four in the pale form. The eyespots and spots on the petals and sepals are a reddish brown color.

Stanhopea oculata (gold form) flower

This form also has a different fragrance that is similar to Eucalyptus, or a little like camphor.  This fragrance tends to align with the 1.8 cineole identified for most S. oculata in a study conducted by Witten and Williams in 1992.  This is a different fragrance than the other form I have that resembles chocolate mint with vanilla.  This is a great form of S. oculata that should be in everyone’s collection.

Stanhopea Fall Culture Checklist

 

As the weather begins to cool, fall is a great time to enjoy Stanhopea blooms and watch new growths emerge.  This is also a good time to repot or rebasket plants because it is still warm and many Stanhopea will continue growth through fall.  By the end of December, most warm growing Stanhopea will complete their growth cycle, and wait for spring/summer to continue growth in preparation for summer or fall bloom.

 

·         Continue watering all Stanhopea regularly and keeping them moist.  I usually water these orchids three to four times a week under normal temperature conditions.  If temperatures rise above 90°F (28°C) and humidity is low I mist and lightly water every day.  Guarding against low humidity is particularly critical growing Stanhopea outdoors in southern California due to the Santa Ana winds we often receive.  These winds are warm to hot and are devoid of humidity.  By the end of fall you can often begin to reduce watering slightly to just two times a week, or less if rainfall is plentiful.

·         Continue fertilizing all species regularly.  I often reduce the manufacturer’s recommendations to one third or one half and fertilize every week, or what is known as weakly-weekly.  Stanhopea can be rather heavy feeders when they are in active growth.

·         Fall is an excellent time to repot smaller Stanhopea or larger baskets.  I usually wait until mid to late October to rebasket because this allows the growths to increase in size and makes it less likely that you will injure them.  This is a prime time for growth for several species and rebasketing is advantageous.

·         Weed baskets to prevent ferns and other plants from taking up space in baskets.

·         In mid fall (November) I remove or roll up most of the saran shade cloth and store it until spring.  This allows the Stanhopea to receive more sunlight, albeit diffused light during the fall and winter months.  This will assist those species that grow all year and often complete their growth in the winter.

·         If you know temperatures are going to increase and humidity levels drop, you may want to consider moving a Stanhopea that is coming into bloom to a shadier more humid area, or as I often do onto my covered patio.  That way I can enjoy the flower show right from my window.  This often prevents early desiccation of flowers and they tend to last the average three to five days instead of just two.

·         Throughout fall make sure to check for growing inflorescences and ensure that their growth is unimpeded by other plants or the basket.  If need be place a plastic label underneath the inflorescence to help direct the growth out of the basket.  Some inflorescences may emerge from the baskets as late as November or December in some species.

·         Use of a methaldihide product or an organic substitute such as Sluggo is advised on a weekly basis at this time to prevent slugs from disfiguring new growth and impacting new inflorescence and bud growth.  I often use a product called “That’s It” that is a granular form and therefore leaves less residue in the growing media.  I am currently testing Sluggo as a more organic method of slug control.

·         Check for spider mites through fall as our weather is still warm and dry.  Small yellow spots on the foliage signal that these pests are active on your Stanhopea.  Spray infected areas with rosemary oil spray or an insecticidal soap to kill the pests as soon as possible to prevent them from damaging the plant further and spreading to other orchids.

·         You should also be diligent in keeping watch for fungus infections at this time on leaves.  Several fungus attack leaves when humidity is high and temperatures are warm. Black or brown spots of leaves and yellowing of leaves in odd patterns are usually the cause of fungus or bacterial infection.  Treat with a fungicide or bactericide.  I often use Physan 20 to deal with the problems and prevent further damage to the plants.

·         The warmer temperatures and reduced breezes combine to cause fungal infections such as black spot on some Stanhopea species and hybrids.  The key to reducing this problem is to make sure your Stanhopea are grown in a breeze way that gets constant air flow, or to place a fan in the growing area that produces a very slight breeze at all times.  This will prevent the fungus from settling on the leaves and disfiguring them.   This problem does not impact the health of the plant to a large degree but it does look unsightly.

Stanhopea tigrina 'SanBar Gold'

S. tigrina var. nigroviolacea 'SanBar Gold'

   

This is another spectacular form of the Mexican species Stanhopea tigrina var. nigroviolacea.  These are the first flowers that have been produced by this plant, but it is a rather vigorous form and produces several growths per year.  I am looking forward to additional inflorescences next year. The flowers have some of the most intense colors of yellow-gold I have seen in this species.  The infusion of gold is most prevalent at the sepal and petal tips and even into the horns.

 

S. tigrina var. nigroviolacea 'SanBar Gold'
showing gold color on back of sepals

The deep gold color is also infused into the back of the petals which makes the flower glow a brilliant golden color.  The back of the petals of the other forms I have are a buff or light yellow in color.  These color combinations make this form a winner in my opinion, especially because of the gold combined with the deep oxblood color of the petals and sepals. 

Stanhopea ruckeri var. alba

This is the form of S. ruckeri that lacks red in the flowers, with no eye spots and no red spots on the petals, sepals, hypochile and column.  The flower is a clean off-white color with green to green blue color infused into the sepals and petals.  The hypochile is a deep yellow color at the base and ivory white on the epichile.  The column is white with a well-defined blue-green infusion of color in the center that is often not captured well in photographs.  Altogether this is a good representative of the crisp and clean color combinations of an alba form of S. ruckeri in sharp contrast to the red spotted form.

S. ruckeri var. alba flowers

S. ruckeri var. alba column with blue-green coloration

 

The fragrance of this flower is very light and almost undetectable.  It favors a slight fresh baked bread scent mixed with lily.   It would seem that this is the form that was given the specific epithet of inodora for its” lack “of fragrance compared with other more fragrant Stanhopea.  This orchid also resembles the plate of S. inodora found in Edward's Botanical Register and published in 1845, from a plant that was imported from Mexico.

Stanhopea stevensonii

This orchid is native to Colombia.  It grows in intermediate to warm mountain forests at approximately 1,312 feet (400-m) in elevation.  This species requires shade and copious amounts of water.  I grow the plant on the north side of my house, and  it appears to need more shade thus it grows better here than with greater sun exposure.  This species has golden yellow flowers with pale red eye spots on the upper hypochile, and few small red spots on the petals and sepals.  There are also small red spots on the epichile and column.  The fragrance of this Stanhopea is difficult to describe and smells sweet but rather chemical-like.  The fragrance is similar to sweet grass with trace amounts of fresh pine needles. Some individuals have described the fragrance as being similar to moth balls, but I have not detected this fragrance in fresh flowers. 

Stanhopea stevensonii inflorescence

 

The flowers are 3.0 to 3.2 inches (7.6 to 8.1 cm) wide with several flowers (5-7) on an inflorescence.   The inflorescences are rather short, to 6 inches (15.2 cm) in length.  This is one of the smaller Stanhopea with short inflorescences, so it is best to grow it in a small basket.  I grow my specimen in an 8 inch (20 cm) basket and it has been doing well in that size basket for years. The leaves of this orchid are a light green, and are 7.5 to 10.5 inches (19 to 26 cm) long and 3.9 to 4.8 inches (10 to 12 cm) wide.  The pseudobulbs are 1.6-2.2 inches (4.0 to 5.6 cm) long and deeply furrowed. 

Stanhopea stevensonii flower

Cirrhaea dependens

This is a small to medium sized orchid that is native to Brazil and found in seasonally dry forests from elevation of 2,297 to 3,937 feet (700 to 1200 m).  The orchid grows in warm locations and requires part shade to prevent the leaves from burning.  It does well in conditions that are similar for growing most Gongora.  The inflorescences are pendulous  1.0 to 1.3 feet (30-40 cm) long, and emerge from the top of the growing medium, so it is best to grow this orchid in baskets.

Cirrhaea dependens flower "dark form"

The flowers are resupinate so even though the inflorescence grows down, the labellum faces up and opens partially.  The flowers can have a green to yellow background with pink to red spots over the petals and sepals.  The form that is in this photograph is the” dark form” with deep maroon markings on the sepals and petals.  The flowers are also short lived similar to Stanhopea and last for only a few days.

Cirrhaea dependens inflorescence
with partially opened flowers