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Dendrosenecio keniensis
''Dendrosenecio keniensis'' (syn. ''Senecio keniensis'' and ''S. brassica'') is one of the giant groundsels endemic the higher altitudes of Mount Kenya. It is in the family Asteraceae and the genus ''Dendrosenecio'' (previously a ''Senecio''). ''Dendrosenecio keniodendron'' occurs the upper alpine zone of Mount Kenya and ''D. keniensis'' in the wetter areas of the lower alpine or the moorlands.
==Description==
;Leaves and stems: Prostrate (even subterranean) trunks of soft brittle wood, with trunk to in diameter; which branch repeatedly at or below ground level, forming a large prostrate clone.〔 The branches each support a great cabbage-like,〔 densely packed leaf-rosettes of 30–40 leaves; each branch cloaked with older, dead foliage. Branches produced near ground-level are capable of rooting that supports a "creeping" horizontal growth-form.〔 The leaves are oblong and narrow slightly where they attach to the rosette; they can be up to long and wide. The leaves are capable of secreting limited quantities of a mucilaginous fluid containing polysaccharides. The upper leaf surface has a hair cushion which is also often coated with dried mucilage. The lower surface is covered densely with a thick, white felty covering of lantate hairs.〔 Growth rates are very slow.〔
:''S. keniensis'' is frost resistant to 〔 〕 This ability to withstand the colder temperatures that occur in the upper altitudes of Mount Kenya is in part due (at least in Lobelias) to the large amounts of mucilage which are contained by the rosettes of leaves which that might assist in preventing the leaf bud from freezing and the reservoir of fluid from evaporating. As well as the nyctinastic behavior of the leaf rosettes which open during the day and close tightly around the leaf bud and meristem when it becomes cold at night;〔 the outer leaves bend inwards and form around the central leaf bud.〔 〕
;Flowers: Tall terminal spikes of groundsel flowers arise from each of the great cabbage-like rosette of leaves,〔 each spike or inflorescence narrowly conical up to tall and in diameter. The flower heads are upright (as opposed to pendulous in ''D. keniodenron'')〔 each consisting of 12 to 16 bright yellow ray florets up to long and 60-80 disc florets.〔 Each leaf rosette dies after flowering, but the plant lives on because its highly branched growth form consists of multiple rosettes.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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