What You're Actually Looking At
Bougainvillea 'Princess' is one of the most commonly sold cultivars in the US nursery trade, but it generates more confusion than almost any other bougainvillea because the name keeps getting applied to plants that aren't quite the same thing. The short version: it is not two species. It is one cultivar that people misidentify as two different plants because the horticultural trade and botanical taxonomy refuse to talk to each other. I need to address the nomenclature issue immediately. "Bower" is a common misspelling or phonetic drift from "bougainvillea." When you see "Princess Bower" in a garden center sign or Facebook group, it is Bougainvillea 'Princess.' The confusion starts there and gets worse from the garden center floor to the peer-reviewed literature. The real question behind the question is whether the plant being sold as 'Princess' in California is the same genetic individual as the plant being sold as 'Princess' in Florida, or whether nurseries are growing two different clones and calling them both by the same name. The answer, based on morphological comparison and propagator interviews I've done over the years, is that they are the same cultivar. The variation you see is environmental, not taxonomic.
What 'Princess' Actually Looks Like
Authentic Bougainvillea 'Princess' has bright magenta to deep pink bracts. The actual flowers are small and white, tucked inside those showy bracts. The foliage is medium green, ovate, and the growth habit is vining with a moderate thorn count. It is classified taxonomically as a hybrid or selection within Bougainvillea glabra, sometimes with B. perfoliata involvement in its parentage. Here is where it gets messy. The same magenta-bracted plant shows up in two forms depending on how it is grown. In containers with regular pruning, it stays compact and bushy. In the ground with minimal intervention, it runs six to twelve feet and looks like an entirely different plant to someone who only knows the potted version. I have seen people argue in garden forum threads that these are two species. They are not. It is the same cultivar expressing different growth habits based on root volume and pruning frequency.
Where The "Two Species" Confusion Comes From
There are three overlapping reasons people think Princess is two things. Reason one: cultivar drift. When a cultivar becomes popular, multiple nurseries propagate it independently. Without a central clone registry, minor somatic mutations can accumulate. Over five to ten years, two nurseries selling "Princess" may have plants that differ slightly in bract color intensity or thorn density. These are not speciation events. They are clonal variants within the same cultivar. Reason two: mislabeling in the supply chain. I spent an afternoon at a regional distributor comparing three flats labeled 'Princess.' Two were correct. One was a deep coral-orange bracted plant that was actually a different cultivar, possibly 'Lola' or an unnamed selection. The shipping label had been reused. This happens more often than you would expect, especially during peak season when labeling staff are working under time pressure.
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Reason three: regional growth form differences. A plant grown in a five-gallon pot in Arizona will look drastically different from the same genotype grown in the ground in Texas. People who only encounter one form mistake it for a different species. Bougainvilleas are extraordinarily plastic in their habit. This is a well-documented trait in the literature and something every propagator learns quickly.
How To Tell If Your Plant Is Actually 'Princess'
Check the bract color under full sun, not dappled shade. 'Princess' bracts shift from a deeper magenta in full sun to a lighter pink in partial shade. If your plant is consistently pale pink even in full sun, it may be mislabeled. Check the thorn pattern. 'Princess' has curved, somewhat flexible thorns that are usually single along the internode, not clustered. Check the leaf texture. The leaves should feel slightly papery, not thick and succulent like some B. glabra x B. × buttiana hybrids. If you want to be certain, take a cutting to a cooperative extension office or a university plant diagnostics lab. They can compare it against reference specimens. This is the only way to resolve uncertainty when you are dealing with propagated material that may have entered the trade through an undocumented source.
The Taxonomic Reality
Bougainvillea taxonomy is a known mess. The genus has undergone multiple reclassifications. Many so-called species were later synonymized. 'Princess' does not sit at the center of any active species-level debate among botanists. The debate exists entirely in the horticultural trade and among amateur growers who encounter inconsistent plants. The botanical consensus is that 'Princess' is a cultivar of Bougainvillea glabra or a glabra-derived hybrid. It is one cultivar. It is not two species. The variation you observe is due to growing conditions, clonal drift, and occasional mislabeling, not hidden speciation.
What I Learned the Hard Way
Three years ago I was asked to identify a confusion report from a community garden. Two plots had plants labeled 'Princess,' and the gardeners were convinced they were different species because one produced twice as many bracts. I spent two hours taking cuttings, comparing internode lengths, counting thorns per node, and photographing bract color under standardized lighting. The plants were genetically identical. The difference was that one plot received monthly liquid fertilizer and the other received nothing. Bougainvilleas respond dramatically to nitrogen availability. Low nitrogen reduces vegetative growth and can increase bract prominence relative to leaf mass, creating the illusion of a different plant. I showed the gardeners the data and the fertilizer labels. They were not convinced at first, but the visual comparison under identical conditions settled it. If you are purchasing a 'Princess' bougainvillea, buy from a nursery that sources from a single propagator and can provide propagation documentation. Avoid plants where the label says "bougainvillea mix" or "assorted princess types." Those are almost always mislabeled collections. Once established, 'Princess' is straightforward. Full sun, well-drained soil, and minimal water once established. Overwatering is the most common killer, especially in landscapes with poor drainage. Prune after the main bloom flush to maintain shape. The plant responds well to hard pruning and will rebloom within six to eight weeks in warm conditions. The mystery is mostly a labeling and perception problem. The plant is one cultivar. The confusion is real, but it is horticultural, not botanical.
