Family: Stylidiaceae
Stylidium
Citation:
Sw. ex Willd., Sp. Pl. 4:146 (1805).
Derivation: Diminutive of Greek stylos, column; referring to the sensitive column consisting of the fused stamens and the style.
Synonymy: Not Applicable Common name: Trigger-plants.
Description:
Annual or perennial herbs with leaves usually in a basal rosette rarely along the stems; leaves sessile or petiolate, alternate, opposite or whorled, usually entire or rarely with sharp serrations.
Inflorescence a thyrse with 1-few monochasia either corymb-like with younger flowers slightly overtopping the older ones, or raceme-like with monochasia reduced to single flowers (subtended by 2 bracts), usually glandular-pubescent; sepals scarcely connate or unequally fused to form 1 or 2 lips; corolla with a short tube and often split along the one side next to the labellum, zygomorphic with corolla lobes vertically or laterally paired rarely subequal and radiating; labellum (fifth petal) much shorter than corolla lobes, recurved and not irritable; column (fused style and stamens) usually irritable, recurved, with terminal anthers laterally and stigma below, resting in the labellum, but jerked erect when activated; ovary inferior more or less 2-celled with many ovules on a usually stalked central placenta.
Distribution:
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136 species mainly in Australia but also from New Zealand to South-East Asia.
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Biology:
No text
Key to Species:
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1. Perennials; leaves numerous in dense rosettes; flowers subtended by 2 sterile bracts |
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2. Leaves 5-30 cm long, in 1 basal rosette |
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S. graminifolium 4. |
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2. Leaves 0.5-0.9 cm long, in several rosettes along the stem |
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S. tepperanum 7. |
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1. Annuals; leaves alternate, opposite or if in rosettes then up to 8; flowers without sterile bracts |
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3. Ovary globular; sepals equally connate |
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4. Upper pair of petals truncate and variously lobed; column with a basal tooth |
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S. calcaratum 2. |
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4. Upper pair of petals with a rounded apex; column without a spur |
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S. perpusillum 6. |
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3. Ovary obconical; sepals unequally connate |
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5. Leaves along the stem and internodes visible at least between some of them; stem more or less fleshy |
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S. despectum 3. |
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5. Leaves in a basal rosette; stem fleshy below the leaf rosette |
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6. Corolla lobes radiating; column insensitive and not activated |
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S. beaugleholei 1. |
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6. Corolla lobes unequally laterally paired; column sensitive and activated by pollinators |
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S. inundatum 5. |
Author:
Not yet available
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