PLANTS AND PEOPLE - Botany 328 - LECTURE NOTES
- FALL 1997
Hugh D. Wilson - rm. 306, Butler Hall
7 October 97
Tropical
gynoecia
1. HESPERIDIUM:
a berry (syncarpous, fleshy, indehiscent) with a leathery rind [exocarp
+ mesocarp] with embedded oil cavities and locules filled with 'juice sacs'
[unicellular 'hairs' derived from the endocarp - each internal 'segment'
represents a carpellary unit. Fruit type common to the RUTACEAE
and uniform in the genus Citrus.
a. The genus is native to Asia and the South Pacific - domesticates
transported early to Europe, later - by spanish - to the New World (Florida
1565 - important by 1820).
b. Oranges (Citrus sinensis) largest perennial fruit
tree crop in the U.S. and 'most grown' Citrus crop of the world. Normal
type 'Valencia' - most important type grown in Florida and Texas - 'Navel'
[mutant with non-functional, small ovary on top of the functional ovary
- forms the 'navel' - is sterile [seedless].
c. Coloration induced by cool weather - chlorophyll degrades and other
pigments become evident - does not occur in the topics - thus, treat with
ETHYLENE - HORMONE TO STIMULATE FRUIT MATURATION - or actually dye the
fruit orange.
d. Citrus aurantiifolia - 'lime' - scurvy - now known
caused by lack of vitamin C - British only knew that daily ration of lime
juice prevented the disease - 'limeys' - vitamin C content of limes very
high.
e. Grape fruit - C. paradisi - evidently a hybrid between
two citrus species (one the sweet orange) that occurred in the New World
- thus, New World origin of a domesticate from a genus that is of Old World
origin.
2. PEPO: a berry from an epigynous species, thus the outer rind
a combination of pericarp and perianth tissue - usually leathery or hard
- often with just 1 locule (pumpkin) and three carpels. CUCURBITACEAE
a. Cucurbita
- Pumpkins and squashs: american trilogy - winter vs. summer - immature
vs. mature
C. pepo - Mexico (ornamental, acorn, etc) - C.
texana
C. moschata -most ancient - both North and South Ameica
- butternut
C. maxima - largest 'big max pumpkin' - over 600lbs from
1 gynoecium - largest angiosperm fruit - SA only
C. mixta (C. argyrosperma)and C.
ficifolia - cushaw, uplands
b. watermelon - Citrullus
lanatus - !kung - africa origins
c. Cucumis
- melo - cantolope, sativus - cucumbers
d. Lagenaria
- gourds - similar to Gossypium - very old in Old and New
World
e. Chayote - Sechium edule - single seed
f. Luffa - vascular strands
3. BERRY - SOLANACEAE
- NIGHTSHADE FAMILY - EUROPE - ALKALOIDS - ATROPA
BELLADONNA [DEADLY NIGHTSHADE], MANDRAKE - discovery of New
World:
PEPPERS
[SWEET CAPSICUM ANNUUM] - native to New World - domesticated
in Mexico - paprika - taken up by Old World people -sweet types evidently
derived recently from original, pungent varieties.
TOMATO
Lycopersicon esculentum - (probably better treated as a Solanum
species) domesticated in the New World - initially thought to be poisonous
- 1820 COLONEL ROBERT GIBBON - EAT TOMATOS 'LYCOPERSICON = JUICY
[esculent] WOLF PEACH - again - Italians took up the plant in a big way.
Old World domesticate of the family - EGGPLANT [VS. SOLANUM TUBEROSUM]
[SOLANUM MELONGENA] - big genus - India or China - original
cultivars had an egg-like fruit (small, ovate, white)
4. Moraceae
- Fig - Ficus
- 800 species - large genus of the tropics, many huge trees, dominants
of the tropical lowlands with great ecological importance - also many ornamental
figs - Ficus carica - multiple fruit, unisexual flowers,
fleshy receptacle - SYNCONIUM - pollinated by tiny wasps
that move from synconium to synconium laying their eggs in ovarys of pistillate
flowers. SMYRNA figs have no staminate flowers in inflorescence.
Thus, wild figs or cultivated 'pollen donor' figs (CAPRIFIG) must
be present. This relationship was not understood with figs were first transported
to the New World.
Return to Course syllabus, or prior
session or next session