1. Review conduplicate carpel theory (image) or 'foliar theory' [book]
2. Review fusion of carpels (apocarpy vs. syncarpy - image) - redefine fruit then: 'true' fruit (mature ovary) vs. 'fruitlike' structures - aggregate 'fruit' - multiple 'fruit' - pome
3. Demonstrate with Rosaceae:
Four subfamilies [-oideae] that carry a common androperianth [CA5 CO5 A numerous] that can be arranged from primative to advanced on the basis of the gynoecium:
1. Spiraeoideae: G3-5 - hypanthium present - carpels several and NOT fused (APOCARPOUS - SIMPLE PISTIL), fruit DEHISCENT ALONG ONE SUTURE AND MULTI-SEEDED, GYNOECUM UNICARPELLATE = FOLLICLE. If you have a similar dry, dehiscent fruit that is derived from a COMPOUND PISTIL [more than one carpel - SYNCARPOUS], the fruit is called a CAPSULE. This subfamily small, most conspicuous element of the ethnoflora is Spiraea, an ornamental shrub.
2. Rosoideae: - carpels NOT fused and numerous, but each with only one seed and all AGGREGATED onto the RECEPTACLE at maturity = AGGREGATE 'FRUIT' - genera of the ethnoflora:
Rubus spp. - Blackberry [Dewberry], Raspberries, Loganberries [hybrid type produced by crossing European and American cultivars from the northwest] - true fruit for Rubus is a DRUPLET. If you have ever picked dewberries you know that they stain - this pigment - which is obviously edible - is used by the USDA to label graded meat as 'prime', 'choice', etc.
Fragaria X ananassa - strawberry - stoloniferious [producing stolons = above ground rhizome - 'strewing' [old english] itself across the ground - strawberries harvested by tribal, pre-agricultural peoples of both Europe and the New World - domestication occurred ONLY by native Americans in Chile to produce a domesticated form of F. chiloensis [Island of Chiloe off the coast of Chile - South American center of domestication]. This was brought to Europe, as was a species from the eastern U.S. and Canada - F. virginiana - these two crossed in European gardens [about 1740] - to produce the hybrid lineage that produces the structures that we find in our markets - F. X ananassa. What are these structures? What is the 'X' all about? (polyploidy in the genus)
Rubus gynoecium = fruit = druplet - expanding receptacle of Fragaria - true fruit = ACHENE.
3. Prunoideae: G1 - fruit a drupe - elements of the ethnoflora:
Cherries - Prunus avium [sweet] and P. cerasus [sour]
Peaches - P. persica [3rd - behind oranges and apples - most important fruit crop in US [peaches grown by Native Americans in US Southwest - transport from the South]
Plums - P. domestica
Apricots - P. armeniaca
Almond - P. amygdalus
(name used in your book, name in current use and probably correct is: Prunus
dulcis (P. Mill.) D.A. Webber)- comes from a plum-like drupe,
mesocarp removed during processing - have to remove the endocarp to get
to the seed - like the coconut, the unshelled almond is a pyrene
All domesticated in Eurasia, although native american species of cherries and plums (Prunus mexicana - Lick Creek Park)
4. Maloideae: - G5 - carpels fused (syncarpous) and enclosed in the hypanthium - image - we eat the hypanthium [floral cup - book] and throw away the true gynoecium as the 'core'. (image) Elements of the ethnoflora
Malus pumila - Apple
Pyrus communis - Pear
Cydonia oblonga - Quince
Evidently native Malus species in the New World, but all domesticated species of the Maloideae come from Eurasia - "As American as Apple Pie"? - also the Rose - genus Rosa [Type genus of the Rosoideae] - native American species - National Flower - but domesticates are also Eurasian
Vitis (Grape) - Vitis vinifera - major domesticated wine grape - European
North American species of the genus co-evolved with an aphid-like insect that lived on the roots (Phylloxera), many of our species were naturally resistant to the bug. Phylloxera was accidently transported to Europe in the 1850's when Europeans were using wild North American Vitis germplasm for V. vinifera improvement through breeding. It escaped and spread, and - with no resistance in European vinifera cultivars - came to threaten the entire European crop of wine grapes. Problem was solved by either grafting vinifera plants to North America Vitis rootstock, or breeding resistance into vinifera cultivars from North American species. Thus, American Vitis VERY important for the world's grape crop. Chilean wine, derived from old world vinifera populations that have been isolated from this exchange, remains PURE vinifera.
Also V. lambrusca
- base species for selection of North American Concord grapes.
Blueberry - Vaccinium corymbosum - high-bush blueberry - partially domesticated (floral deveopment - epigyny)
Cranberry - V. macrocarpon - a bog-dweller of the northeastern US - cultivated (long-section of flower)