Citrus flowers

Citrus x sinensis. Ellen Levy Finch. Wikimedia Commons.

One could easily write a book about Citrus and what the genera has done for the fragrance industry. Citrus are easily the most useful and versatile plants in perfume because so many parts can be used. There is Neroli oil, which is distilled from the blossoms of the bitter orange tree (Citrus x aurantium), one of the most common oils used in perfumery; petitgrain oil, distilled from the leaves and green branches of the same species; and finally, the citrus oils themselves used in all kinds of flavorings, air fresheners, etc. Again, it would take an entire book to talk about the many uses of all the different Citrus species in perfumery, and the flavor and scent profiles of each plant. There are so many species and crosses (some which we probably haven’t even discovered yet) to detail, it becomes a logistical nightmare to catalog them all.

Even the scents of each have different profiles, much like the taste of the fruits. While one can easily say it has a citrus and sour taste, they are actually much more complex than merely being citrusy or sour. The flowers very delicately echo this phenomena, each having a very similar scent, but slight differences worth noting. I’m not even going to pretend I have smelled the flowers of each Citrus genera and cross, but I can certainly attest to the big four: lemons, limes, oranges, and grapefruit. To get an idea of the difference, its about like it is with the taste of the fruits. Subtract the sourness and you begin to get an idea of the subtleties of the unique sweetness of each.

One thing these plants have in common besides their popularity is their bloom period- its normally in the dead of winter. This actually is a bonus for us since we get to appreciate their fragrance in greenhouses this time of year when not much else is blooming, but also is a bonus for the bees that pollinate them since there is not much competition around. Another post entirely could be made for the honey difference from each of the flowers, but I’m not even nearly confident enough to address that either! While us northerners are derelict to only growing them in greenhouses, our neighbors to the very deep South and California get to enjoy growing them outside where law permits. For those who don’t know- if you live in certain Citrus-producing counties in the South, it is illegal to grow your own citrus plants for fear of disease outbreak and cross-pollination, so please make sure you are legally allowed to grow your own citrus before you attempt it!

Now there are such thing as hardy citrus, the hardiest being Trifolate orange, (Poncirus trifoliata) that are hardy to zone 5 (Chicago, Milwaukee, Detroit, Cleveland, etc.,) but the fruits are not edible and are very sour/bitter. The plants do have sweetly fragrant spring-blooming flowers, and spicily-scented leaves however, so its not quite useless beyond the novelty factor.

Poncirus trifoliata. Kurt Stüber. Wikimedia commons.

Now for the subtleties in the flowers of the big four. I can compare fruits and petitgrain oils in another post to save this one from being too lengthy, as well as a list of fragrance comparisons (i.e. lemon verbena smelling like lemons, etc.) Lemons (Citrus x limon and Citrus x meyeri)  are actually a rarity among other citrus plants, since they have more than two bloom periods and flowers can appear with fruit. The flowers are often purple-tinted and sweeter than orange blossoms to my nose, with a definite lemony-flair along with the standard orange blossom fragrance. Limes (Citrus aurantifolia and Citrus x latifolia) are the easiest to grow in indoor containers as they are smaller than the other citrus species, and also feature purple-tinged flowers like lemons and grapefruit. An added bonus of key limes (C. aurantifolia) is that they are in essence ever-bloomers in warmer climates and provide a steady stream of flowers and fruits (other lime species may show this characteristic but I’m not 100% positive on any one cross or subspecies.) The fragrance of lime blossoms is much more delicate than any of the other big three, with a light lime scent in addition to the standard orange blossom sweetness. The lime flower essence does not carry as much as the others but makes a wonderful blossom water.

Orange blossoms are the prototype to explain the scent of the blossoms of others, as well as provide a comparison for the scent of many other plants called Mock Orange. Orange (Citrus × sinensis) and its many crosses are a perfumers delight since the flowers have a sweetness like heaven itself that provides the nose with a certain pleasure during the cruel winter weather. How does one explain the fragrance? Sweet doesn’t even cut it. Honey-like is closer; heavenly even halfway true. Delectable maybe? Ok, its like fresh laundry covered in honey and sugar, with a very light essence of orange minus the sour overtones. While many plants want to try to claim their scent to be like orange blossom, they really don’t come close to matching its sweetness, and ultimately one just has to smell it for themselves to get the real picture.

Last is Grapefruit. Citrus × paradisi is much more known for the unique sourness of its fruit than the scent of its flowers, but oh my if they aren’t the most fragrant of all the Citrus! Maybe it is because like the fruits, the flowers are also larger, thus the scent must be grander to compensate. The scent is almost exactly like orange blossom, but stronger and without the slight citrus tone- it is just marvelous! It has been a few years since I have smelled grapefruit flowers, since the plant is not as readily grown as the other big three citrus, but I remember the scent like it was just yesterday- permeating the entire greenhouse of the nursery where they were being grown. The scent carries much farther than other citrus species I have encountered to date, and I would love to try the honey coming from these flowers above all other citrus honey. Who ever knew the most sour of the big four citrus would be the sweetest flowering one?

If Citrus isn’t the single-most useful angiosperm Genus on the planet, I would be very surprised to see what overtakes it. Aside from the usefulness of the leaves in Asian cuisine, and palatability of the fruits; the plants are worth growing for the scent of the flowers alone. Anyone with a greenhouse would be seriously remiss without at least one citrus plant in it. One more interesting point to mention- if you happen to eat Miracle fruit (Synsepalum dulcificum) before eating Citrus, the fruits lose all their sourness and taste almost exactly the way the flowers smell. It is a neat way to enjoy the true sweetness the fruits offer.