Seed (種子)

[plant anatomy, plant morphology, seed germination]

Ovule

Structure of Ricinus communis seed

Roles of seed coats, including nut wall

• barrier to germination cues, including light
• barrier to seed predators
• barrier to light
• pulp attached on vertebrate-dispersal seeds
• rich in secondary defensive compounds

Funiculus (珠柄): a stalk connecting an ovule or a seed with the placenta

Related to animal dispersal

rich in lipids and proteins → carried (= dispersed) by animals, mostly by ants
Ex. Robinia pseudoacacia, Luzula capitata

Pericarp (果皮)

sorosis (肉質集合果): derived from just the pistils of many unisexual flowers of an inflorescence. Ex. mulberry (Morus)
syconium (無花果状果): derived from numerous ovaries borne on the inside of the fleshy receptacle of an inflorescence. Ex. fig (Ficus)
cone (球果): seeds enclosed by numerous, thickly-lignified scales that are overlapped around central axis. Ex. pineapple (Ananas comosus)

2. flesh of fruit derived from a hypanthium that surrounds the papery carpels _____ pome (梨状果/梨果) Ex. apple, pear, quince (マルメロ)
2. flesh of fruit derived from the ovary wall

3. pericarp with an outer fleshy layer and an inner bony layer (the stone) _____ drupe or stone fruit (核果/石果): (= putamen 果核 = 種子) Ex. peach, cherry

drupelet (小核果): each of small, individual drupes in an aggregate fruit, represented by Rubus

Strawberry fruit
individual fruits = true fruit (fruitlet)
berry (enlarged receptacle) = false fruit

3. pericarp without an inner bony layer, more ore less fleshy throughout _____ berry, bacca (液果/漿果): Ex. tomato, grape

simple berry (単漿果): berry consisting of mono-carpel Ex. Schisandraceae, Berberidaceae
compound berry (複漿果/漿果): consisting of poly-carpel Ex. Vitaceae, Sonalaceae

4. septa evident in crossection; the outer layer leathery _____ hesperidium (柑果/ミカン状果) represented by citrus (柑橘類)

Hesperidium (berry with a leathery rind)
Ex. lemon (Citrus lemon) fruit

4. from a simple pistil, often with a thin shell but not bony

2. fruit indehiscent (not splitting open) - indehiscent fruit (不裂開果, 閉果)

3. with one or more wings - samara (翼果, 翅果): wing derived from the elongation of pericarp (maple, ash, elm)

(s.s.) wing-like on a part of pericarp → not including wing derived from calyx

3. without wings

4. from a composed pistil, becoming hard and bony-shelled - nut or nutlet if small (堅果): Ex. oak, walnut, hazelnut

nutlet, nucula, nucule, nuculanium (小堅果): small nut(often categorized into achene) Ex. Polygonum, Betula, Carex
utricule (嚢果): particularly for nutlet of Carex

4. from a simple pistil, often with a thin shell but not bony

Achene (Lactuca scariola)

5. pericarp fused to the seed _____ grain (caryopsis) (頴果/殻果): Ex. rice, wheat, corn
5. pericarp separable from the seed _____ achene or akene (痩果): Ex. aster, sunflower, sedges

cypsela (pl. -e) (下位痩果, 菊果): false fruit, consisting of plural carpels on ovary inferior and fusion of pericarp and calyx tube, generally categorized into achene

2. fruit dehiscent (splitting open) _____ dehiscent fruit (裂開果) (dehiscing 裂開している)

3. from a simple pistil (one carpel)

4. splitting on two suture (consisting of one carpel dorsabdominally dehisced) - legume (豆果) or pod (莢果) Ex. Fabaceae (pea, bean, alfalfa)

loment (節豆果, 節果): having constrictions between the seeds and that breaks into one-seeded segments at maturity

4. splitting on one suture - follicle (袋果) Ex. milkweed, larkspur, peony

3. from a compound pistil (carpels two or more, united)

4. carpels separating from other but each retaining its seed - schizocarp (分離果) or mericarp (分果) Ex. parsnip (Pastinaca sativa), carrot, spignel (Oenanthe javanica, セリ), honewort

in Apiaceae characterized by two one-seeded carpels which split apart at maturity - cremocarp (双懸果)

4. carpels splitting, releasing one or more seeds

5. fruit two-celled carpels, the two valves splitting away from a persistent, thin partition or septum (replum 隔膜) - silique and silicle (角果)

6. long types - silique (長角果) Ex. rape, radish
6. short types - silicle (短角果) Ex. Shepherd’s-purse

5. fruit one-to-several-celled, the partition not persistent if the fruit is two-celled - capsule (蒴果)

loculicidal capsule (胞背裂開蒴果)
ventricidal capsule (胞腹裂開蒴果)
septicidal capsule (胞間裂開蒴果)
septifragal capsule (胞軸裂開蒴果)
poricidal capsule (孔開蒴果)

6. opening by a lid - circumscissile capsules (circumscissile, adj. 横に裂ける)

7. with a single seed - utricle (胞果) Ex. pigweed, Chenopodium album, Amaranthus
7. with several seeds - pyxidium or pyxis (蓋果), a seed capsule in the form of a box, the seeds being released when the top splits off. Ex. Portulaca, Plantago

6. opening by holes near the top - poricidal capsule (孔開蒴果) Ex. poppy
6. opening by splitting lengthwise

7. splitting on the septae - septicidal capsule (胞間裂開果) Ex. yucca, Hypericaceae, Linaceae, Elatinaceae, Lythrum, Rotala)
7. splitting between the septa and in the locules or chamber - loculicidal capsule (胞背裂開果) Ex. glacier lily, Epilobium，Oenothera，Pyrola，Lilium，Iris)
7. opening, or dehiscing, by the breaking away of the outer walls of the carpels from the partitions - septifragal capsule (胞軸裂開果): Ex. Convolvulaceae