How do you know your Stanhopea is happy?

 

Stanhopea shuttleworthii in bud

Other than the rather easy answer that your Stanhopea blooms consistently for you every year, there are other signs to observe that can help you understand how well your Stanhopea is growing.  A flowering Stanhopea is usually a content Stanhopea. I have noticed that they will not flower if they are severely stressed or not in the correct environment.  A Stanhopea that consistently produces several inflorescences every year is large enough and being provided the right care in order for it to put a great amount of effort and resources into flowering well.



Stanhopea insignis exhibiting older robust
pseudobulbs and new growth.

A plant that has several new and mature growths is doing well and will have the energy reserves to flower the following year.  A plant that has large pseudobulbs (this varies according to the species) is more likely to produce larger growths and more inflorescences.  Large and firm pseudobulbs are a sign that the plant is doing well.  Some species have folds or wrinkled surfaces such as S. insignis that may look like they are desiccated.  However, if you gently press the pseudobulb between your thumb and index finger and it is firm, then the plant is doing well.  However, if the pseudobulb is spongy or soft, then the plant may be getting either too much or too little water. 




Stanhopea tigrina var. nigroviolacea
producing several inflorescences

Once you have grown your Stanhopea for a few years, you may want to make a trophy plant out of it, re-basket it into a large basket and let it fill the entire container. This will provide you with a massive plant that will produce several if not dozens of inflorescences and bloom for several weeks. These trophy plants are very attractive and show stoppers. However, your orchid cannot remain in the same container forever, and it will eventually decline unless it is divided and re-basketed. Several growers have reported that a Stanhopea that was in decline and not blooming well was invigorated by dividing it and re-basketing the pieces.



Stanhopea gibbosa new root growth

Another sign that a plant is doing well is that it is producing new roots with green growth at the tips, this signifies a growing and elongating root.  The roots should be produced around the base of new pseudobulbs and also throughout the basket. In fact, I usually consider a Stanhopea is doing very well when you can see root growth around the outside edge of the basket.  This signifies that the plant is growing well and producing enough root growth to encompass the entire basket.  This root growth takes advantage of all the water and nutrients in the growing medium every time you water.  Root growth is most evident in the spring and summer months. If roots are not actively growing at this time, you may want to check your plant and make sure that it is receiving the correct amount of water. 

A plant that is not getting enough water will have a growing medium that is dry and the basket will be very light.  Your plant should always be moist, but not sopping wet.  An over dry plant will have roots that will turn gray in color and the roots will begin to die and become desiccated.  If your plant is receiving too much water the roots may not be receiving enough air for gas exchange.  In this last case the media will be soggy and the roots will look very dark brown to black and may be rotting in the anaerobic environment.





Stanhopea Morphology

 

For many of you who grow Stanhopeas, the specific botanical terminology used to identify parts of orchid plants may not be particularly interesting.  However, several species of Stanhopea differ dramatically in physical characteristics.  I think it is always a good idea to know and learn as much as you can about the plants that you are growing to ensure you can accurately identify them to species.  This will give you a great advantage in knowing what conditions the plant would prefer, ensuring that the plant will grow to ultimate size and maturity, and providing you with several blooms.  It will also reduce the chances that you will purchase a plant and not be able to provide the proper conditions to allow the orchid to grow and bloom.

I will be using some botanical terminology from time to time to discuss the physical characteristics of these orchids, so I thought it would be appropriate to provide a post that outlines some of this terminolog.

Stanhopea anfracta flower

Orchids have four main parts to the flower and these include the sepals, petals, labellum (lip), and column. The sepals in Stanhopeas are some of the largest flower structures and are the outer most portion of the flower. The next inner structures are the petals, which are usually thin and often ribbon-like and twist or roll back when the flower is mature. The next inner structure  is the lip which has three parts. The upper portion of the lip that is connected to the rest of the flower is called the hypochile, and is often rounded, cupped, or cylindrical. This is the part of the orchid where the fragrance is produced. The central portion of the lip is called the mesochile and is usually a short piece of tissue that usually has two projections attached to it that are called horns (absent in the hornless species). The lower portion of the lip is called the epichile and is usually spade shaped or tri-lobed depending on the species.   

 

The column in orchids is the organ where the reproductive parts are placed, is the union of both male and female structures, and is the innermost structure.  In Stanhopeas, the column is an elongated cylindrical organ that creates a tight space between the horns and epichile that allows the pollinating insect to be positioned so that the pollen cap is removed, and the pollen sac deposited on the back of the insect. This action also opens access to the stigma to allow pollination to occur by the next insect carrying a pollen sac.



Stanhopea graveolens pseudobulb

Stanhopeas have pseudobulbs that sit at the surface of growing medium and are often rounded or egg shaped. These storage organs are used to store water and nutrients for the plant. The larger the pseudobulb, the more mature the plant is, and the more likely that the pseudobulb will produce an inflorescence (flower stalk). At the top of the pseudobulb is the cylindrical base of the leaf called a petiole, and at the top of that is the blade of the leaf. Below the pseudobulb, roots are produced to allow the plant up take up nutrients and water.

Stanhopea embreei leaf

Leaves of Stanhopeas can be large and widely lanceolate in shape or smaller and almost linear.  Stanhopea leaves can be rather thick and leathery or in some species thin and delicate.  The larger leaved and thin leaved species ( e.g., S. embreei and S. insignis) seem to tolerate less sun, while the narrow and leathery leaved species (e.g., S. oculata and S. tigrina) tolerate a bit more sun, though they can still burn easily in part day sun. Part shade to full shade is best for most species, and I have found an hour or two of very early morning sun tolerated by most species.