Juglandaceae
(Walnut Family)
Habit
-
monoecious trees
Leaves
-
alternate,
pinnately compound,
estipulate; with
peltate aromatic glands
Flowers
- small,
unisexual;
staminate inflorescences are
catkins;
pistillate inflorescences a solitary flower (rarely
catkins)
Sepals
- 4 and
connate in
staminate flowers (4
connate and
adnate to the
ovary in
pistillate flowers)
Petals
- absent
Stamens
- 5-40,
distinct
Gynoecium
- of 2-3
connate
carpels;
ovary inferior
with 1
locule and 1
basal ovule
Fruit
-
nut (or
drupe, sometimes
winged with
adnate
bracts);
When a
nut often surrounded by
bracts that
subtend
the flower that mature to form a
husk.
Nut inside is
fruit that splits in 2 halves along
midveins of
carpels; seeds large with no
endosperm and
massive sculptured
cotyledons
Diversity
- 8 genera / 60 species
Distribution
- mostly north-temperate
Economics
- edible nuts, wood very important in 18th century "the
foremost cabinet wood of North America" All large hickories
cut in 18th-19th century; also walnut oil--hardens but
does not become rancid; excellent preservative for cutting
boards, etc.
- Juglans (walnut) --chambered pith in twigs
- Carya (hickory) --pith not chambered (genus of pecan)
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