All families

For Erik Acharius (1757-1819), Swedish botanist who pioneered the taxonomy of lichens and is known as the "father of lichenology". He was one of the last students of Linnaeus and continued the work that Linnaeus began.
(Ch)

agape, = brotherly love, charity;
anthos, = a flower, the bloom of a flower.
(LS)

ai-, = always;
zoos, = alive, living.
(ability to survive under difficult conditions)
(BL, LS, Le)

alium, allium, = garlic.
(ld)

a-, an-, = denotes privative, negative;
a-, = without, not, -less, un-;
mar-, mor-,= die;
maraino, = to die away, waste away, languish.
marainein, = to wither, decay.
anthos, = a flower, the bloom of a flower.
(everlasting)
(refers to lasting quality of the flowers)
(Ox, ld, LS, Le)

amo, amare, amans, = to love;
-illus, = diminutive.

Amaryllis, = adopted by Linnaeus; name of a country-girl in Theocritus, Ovid and Virgil. Name of a shepherdess.
(ld, BL, Ox, Ca)

ana-, = up, in place or time, back, again, anew;
ana-, = up to, towards, up, in the sense of strengthening;
(upon, up, upwards, above).
cardia, = the heart.
(because the fruits of some species within this genus look like an inverted heart)
(Ox, LS, BL, LS, I8)

anemos, = wind;
anemaios, = full of wind, windy.
anemo-, = pertaining to the wind.

(LS, BL)

anthos, = a flower, the bloom of a flower;
-ceras, from keras, = the horn of an animal; hence ‘horn’.
(a horn, hornlike projection)
(LS, BL)

apis, = a bee.
apium, = parsley, esp. liked by bees; an umbilliferous plant of several species (mountain-parsley, celery etc.). the leaves of one species (water parsley, our celery, the Apium graveolens) were used by the ancients for garlands, on account of their strong fragrance.
(ld)

apo-, api-, = from, away from, out of, asunder, free;
kuon, = a dog (as a word of reproach).
apocynum, = Greek for "dog-away" a family of flowering plants known as the dogbane family, because some taxa were used as dog poison.
(BL, ld, Wi)

Aponus was a hot spring near Padua.
geton, = neighbour.
A partial anagram of Potamogeton, which in turn comes from Patmos, a river, and geiton, a neighbour.
(Le, BL, M)

acer, acris, = sharp, pointed, piercing;
folium, = a leaf.
(having pointy or prickly leaves; the Latin word acrifolium (turned into aquifolium in modern time)
(ld, I10)

aron (ἄρον / αρω / αιρω) = to raise, exalt, extol, exaggerate.
aron = originally from ar- = fire (refers to the bitter taste of the plant)
(LS, K3)

Latinization of the French-Canadian name Aralie for the Ivy Family.
(K3)

a-, = intensive (very much);
sparagmos, sparasso, = a rending, tearing, mangling.
(referring to the sharp spines)
or
spargan, = to be full to bursting, to teem, swell, be ripe.
(to swell or sprout)
(LS, Le)

ασϕοδελ, = (of unknown origin); asphodel. The earlier form, an adaptation of medieval Latin, was affodillus, whence daffodil. The White Asphodel or King’s Spear covers large tracts of land in Apulia, in southern Italy, where its leaves afford good nourhisment to sheep. From the genus the order has sometimes been called Aphodeliæ.
(Ox)

a-, an-, = denotes privative, negative;
a-, = without, not, -less, un-;
splen, = the milt, spleen.
(Asplenium, = a totally confusing reference to the use of spleenwort to cure spleen and liver problems. The name originated with Pliny and Discorides)
(Ox, LS, I11)

astēr, = a star, any luminous body, meteor.
(LS)