I have marked this review with spoilers, because it's giving away more detail than I usually care to give, but there are some actions by the hero that could be considered a deal-breaker by some readers, and it's best they be forewarned.
Flora was the result of a marriage between her English father and a Chinese wife. Orphaned at a young age, she was raised in a Catholic mission in the back-o-beyond western China. When the book begins, it is 1903 and she's seventeen, and the père is beginning to regret giving Flora such an extensive education. Marriage is unlikely, and outside of taking the veil she hasn't got many options - he can try taking her to Shanghai where her options are better - but his health is too frail. It's all too complicated to try and explain, but Flora is brutally attacked, the old père dies, and she's now under the protection of English botanist Mr. Lomax (who is really the powerful and filthy rich Earl of Carlyon). Things get a bit dicey in Shanghai, and Carlyon decides to marry Flora and bring her to England, but he neglects to mention she's going to be the wife of a peer...
Spoilers going forward. Click to read more at your own risk.
As noted previously, Flora was brutally attacked and she's not quite ready to be a wife (at least that's what Carlyon thinks), and since he's an older man of the world used to enjoying the charms of married women...well...when the perfect opportunity shows up aboard ship he doesn't let something like his wedding night stop him. Once Flora starts settling in and ready to respond to her husband, he's off to France and runs into an former mistress and dallies too long and misses his promise to be home for Flora's birthday.
And just when things were looking up for a happy consummation of the marriage, get ready for a Big Misunderstanding that goes on waaaaaay too long. Carlyon gets jealous and how he handles it is not going to endear him to many readers.
Now, how to categorize this book? There isn't enough romance to satisfy a romance reader, and as noted, some of Carlyon's actions aren't going to appeal today's PC minded readers. The historical settings are well done (I really did like the botanist angle, and the descriptions of the Chinese flora), but there isn't enough interaction with known historical people and/or events to tag it as historical fiction, so I'd call this a novel with a historical setting.
I did enjoy the first half of the novel, despite Carloyn's cavalier attitude towards his young wife, but after the Big Misunderstanding started, I was too annoyed to enjoy the second half as much as the first. Four stars for the first part, and two stars for the last part, rounded up to three overall.