Rubiaceae
Alternative names: Not Applicable
Description:
Herbs, shrubs or rarely trees, often with angular stems; leaves entire, opposite, with interpetiolar stipules which are sometimes indistinguishable from leaves (then the collective term 'leaves' is used).
Inflorescence a thyrse or dichasium, rarely fused into a flower head or a single terminal flower, bisexual or unisexual and monoecious or dioecious; sepals 4 or 5, often rudimentary or absent; petals 4 or 5, tubular and connate with the filaments at least at the base; stamens 4 or 5, alternate with the petals; ovary inferior, rarely semi-inferior, with 2 locules each with one to many anatropous ovules on central placentas; style single or 2-fid, with capitate, filiform or mitre-shaped stigmas.
Fruit usually either a capsule, drupe or schizocarp; seeds usually with endosperm.
Distribution:
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About 500 genera and up to 7,000 species found in most parts of the world but particularly well represented in tropical and subtropical regions.
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Biology:
No text
Key to Genera:
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1. 'Leaves' in whorls of 3-12 |
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2. Inflorescence a dense terminal head surrounded by a leaf-like involucre; calyx present |
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SHERARDIA 9. |
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2. Inflorescence axillary or if terminal then without a leaf-like involucre; calyx absent |
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3. Corolla usually funnel-shaped; fruits fleshy, indehiscent |
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ASPERULA 1. |
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3. Corolla rotate with a very short tube; fruit dry, breaking into 2 mericarps |
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GALIUM 5. |
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4. Inflorescence an umbel and/or a capitulum; fruits compound, dehiscing with a lid |
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5. Inflorescence a hemispherical to spherical head; compound fruit dehiscing with many irregular and often oblique lids |
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OPERCULARIA 7. |
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5. Inflorescence apparently umbellate with few to many flower-like connate part-inflorescences; compound fruit dehiscing with a single round lid |
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POMAX 8. |
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4. Inflorescence a thyrse or dichasium or rarely single flowers; fruit simple, if dehiscing then without a separate lid |
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7. Stipules sheathing the terminal bud and scarcely fused to the petioles; plants monoecious; semi-arid regions |
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CANTHIUM 2. |
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7. Stipules fused to the petioles to form a sheath around the node; plants dioecious; coastal higher rainfall regions |
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COPROSMA 3. |
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6. Herbs rarely with a slightly woody base |
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8. Flowers sessile at the nodes |
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9. Fruit fleshy; leaves membranous or almost so |
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NERTERA 6. |
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9. Fruits dry; leaves fleshy |
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DENTELLA 4. |
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8. Flowers stalked or on a stalked inflorescence |
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10. Fruits fleshy; plants dioecious; corolla tube usually as long as or longer than the lobes |
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ASPERULA 1. |
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10. Fruits dry; plants monoecious; corolla tube almost absent |
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11. Calyx absent; fruit breaking into two 1-seeded mericarps |
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GALIUM 5. |
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11. Calyx present; fruit dehiscing by a loculicuidal split to release numerous seeds |
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SYNAPTANTHA 10. |
Author:
Prepared by H. R. Toelken
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