From your list, my favorite combos are [name_f]Felicity[/name_f] [name_u]Juniper[/name_u] and [name_f]Matilda[/name_f] [name_f]Ivy[/name_f]. Other suggestions:
[name_f]Briar[/name_f]: This was the first name I thought of for you. Short and sweet as your husband prefers, but also elegant. Plus, it gives you the nature theme you like.
[name_f]Bronte[/name_f]: For the three incredible authoress sisters. A bonus: This is somewhat obscure, but Australian Olympic swimmer and gold medalist [name_f]Bronte[/name_f] [name_u]Campbell[/name_u] lends an outdoorsy, athletic namesake. I think it would also go well with some of your middle options: [name_f]Bronte[/name_f] [name_f]Josephine[/name_f] or [name_f]Bronte[/name_f] [name_f]Laurel[/name_f].
[name_f]Blythe[/name_f]: Short, upbeat name with a nice meaning. Plus, she is a literary character from one of the aforementioned authors! [name_f]Blythe[/name_f] [name_f]Willow[/name_f] or even [name_f]Blythe[/name_f] [name_f]Matilda[/name_f] are nice.
[name_f]Marguerite[/name_f] nn [name_f]Maya[/name_f]: Your mention of [name_f]Genevieve[/name_f] immediately made me think of this. [name_f]Marguerite[/name_f] was the given name of [name_f]Maya[/name_f] [name_f]Angelou[/name_f], which certainly means this qualifies as literary. A bonus: The meaning is pearl/daisy, so the nature theme is incorporated. I included the nickname [name_f]Maya[/name_f] because I felt that the full name [name_f]Marguerite[/name_f] might not appeal to your husband, but that short and spunky [name_f]Maya[/name_f] might convince him.
[name_f]Marguerite[/name_f] [name_f]Eleanor[/name_f] is lovely.
[name_f]Celia[/name_f] (possible nickname [name_f]Cece[/name_f]): One of the most literary names ever, from the time of [name_m]Shakespeare[/name_m] to now. It is beautiful and packed with meaning, but also short enough for your husband. It strikes me as a wonderful middle ground between [name_f]Genevieve[/name_f] and [name_f]Petra[/name_f].
[name_f]Alexandra[/name_f]: [name_f]Regal[/name_f], royal, and classic, with a fierce meaning and plenty of energetic nickname options. ([name_u]Lex[/name_u], [name_u]Alex[/name_u], [name_u]Lexi[/name_u], [name_u]Andy[/name_u]). Plus, it goes with virtually all of your middles.
[name_f]Sylvia[/name_f] (possible nickname [name_f]Sylvie[/name_f]): This is one of my favorites for you. It has a nature meaning (“forest,”) and is connected to literature through the brilliant (but tragic) Plath. [name_m]Rich[/name_m], historical, and with ties to many cultures.
[name_f]Lilia[/name_f]: One of the most gorgeous nature names. Does not have many literary ties that I can think of, but is the name of trailblazing gymnast and Olympic gold medalist [name_f]Lilia[/name_f] Podkopayeva.
[name_f]Dorothy[/name_f] nn [name_f]Dot[/name_f]/[name_f]Dottie[/name_f]: Another wonderful literature name! Obviously, there is the character from [name_m]Wizard[/name_m] of [name_m]Oz[/name_m], but there’s also the clever, brutally frank author [name_f]Dorothy[/name_f] [name_u]Parker[/name_u]. It has been in use since the 1500s, so it gives you the history and weight that you desire, but also the youthful spunk that your husband gravitates towards.
[name_f]Delphine[/name_f]: [name_m]Rich[/name_m] and feminine, with subtle spunk and plenty of nickname options. A flower name that is criminally underutilized, and has been used in literature by [name_m]Balzac[/name_m]. [name_f]Delphine[/name_f] [name_u]Simone[/name_u] sounds so chic!
Honorable mentions: [name_f]Iris[/name_f], [name_f]Violet[/name_f], [name_f]Flora[/name_f], and [name_f]Dahlia[/name_f]. Best of luck!
And one more: [name_u]Carmen[/name_u]!