Dendrosenecio adnivalis
Encyclopedia
Dendrosenecio adnivalis (synonym Senecio adnivalis) is one of the giant groundsels of the mountains of Eastern Africa. D. adnivalis grows on the Ruwenzori Mountains
and on the Virunga Mountains
in Uganda
and the Democratic Republic of Congo.
3 to 4 centimeters (1 to 2 inches) diameter.
The stems have 25 to 60 leaves densely packed in a rosette
shape at the top. Old leaves are persistent, withered leaf-bases covering the stalk for 1 to 3 meters below the leaf-rosettes. Leaf
surfaces are elliptic to heart shaped and can be 96 centimeters (40 inches) long and 26 centimeters (11 inches) wide, hairy on the top and not hairy on the bottom. Branched clusters of flowers 160 centimeters tall (68 inches) and 60 centimeters wide (25 inches). The droopy flower head
s have 9 to 20 ray florets, 16 millimeters long or no ray florets at all and 90 to 250 disc florets.
n mountains.
Dendrosenecio adnivalis lives at altitudes of 3,000 to 3,800 meters (9,800 to 12,000 feet) on the Ruwenzori Range
with another giant groundsel, Dendrosenecio johnstonii. D. adnivalis more common on the wetter soils.
On the Virunga Mountains
groves of Senecio stanleyi (Dendrosenecio adnivalis) grow after the tree heaths (Erica
sp.) in clearings along with Lobelia wollastonii until the altitude of 4,300 meters (14,000 feet) when vegetation becomes sparse.
A synonym for Senecio stanleyi is Dendrosenecio adnivalis (Stapf) E.B.Knox var. petiolatus (Hedberg) E.B.Knox; for this article, Senecio stanleyi was considered to be a synonym of Dendrosenecio adnivalis.
and on the Virunga Mountains
Virunga Mountains
The Virunga Mountains are a chain of volcanoes in East Africa, along the northern border of Rwanda, the Democratic Republic of the Congo and Uganda. The mountain range is a branch of the Albertine Rift, a part of the Great Rift Valley. They are located between Lake Edward and Lake Kivu...
in Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...
and the Democratic Republic of Congo.
Description
Dendrosenecio adnivalis attains heights of 6 to 10 meters (3 to 11 feet) tall, trunk can be 40 centimeters diameter and the pithPith
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. In eudicots, pith is located in the center of the stem. In monocots, it extends also into flowering stems and roots...
3 to 4 centimeters (1 to 2 inches) diameter.
The stems have 25 to 60 leaves densely packed in a rosette
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...
shape at the top. Old leaves are persistent, withered leaf-bases covering the stalk for 1 to 3 meters below the leaf-rosettes. Leaf
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
surfaces are elliptic to heart shaped and can be 96 centimeters (40 inches) long and 26 centimeters (11 inches) wide, hairy on the top and not hairy on the bottom. Branched clusters of flowers 160 centimeters tall (68 inches) and 60 centimeters wide (25 inches). The droopy flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
s have 9 to 20 ray florets, 16 millimeters long or no ray florets at all and 90 to 250 disc florets.
Distribution
The Congo basin is very wet; humid air is trapped by the mountains and rain falls on most days even in the dryer months. Above 2500 meters (8,200 ft) clouds can persist for several days making the Ruwenzori and the Virunga a wetter environment than the other East AfricaEast Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
n mountains.
Dendrosenecio adnivalis lives at altitudes of 3,000 to 3,800 meters (9,800 to 12,000 feet) on the Ruwenzori Range
Ruwenzori Range
The Rwenzori Mountains, previously called the Ruwenzori Range , and sometimes the Mountains of the Moon, is a mountain range of central Africa, often referred to as Mt...
with another giant groundsel, Dendrosenecio johnstonii. D. adnivalis more common on the wetter soils.
On the Virunga Mountains
Virunga Mountains
The Virunga Mountains are a chain of volcanoes in East Africa, along the northern border of Rwanda, the Democratic Republic of the Congo and Uganda. The mountain range is a branch of the Albertine Rift, a part of the Great Rift Valley. They are located between Lake Edward and Lake Kivu...
groves of Senecio stanleyi (Dendrosenecio adnivalis) grow after the tree heaths (Erica
Erica
Erica ,the heaths or heathers, is a genus of approximately 860 species of flowering plants in the family Ericaceae. The English common names "heath" and "heather" are shared by some closely related genera of similar appearance....
sp.) in clearings along with Lobelia wollastonii until the altitude of 4,300 meters (14,000 feet) when vegetation becomes sparse.
Synonyms
The herbarium has all of the Dendrosenecio adnivalis specimens filed under Senecio johnstonii and indeed, one is probably a variety or subspecies of the other that adapted to live closer to water and on damper ground.A synonym for Senecio stanleyi is Dendrosenecio adnivalis (Stapf) E.B.Knox var. petiolatus (Hedberg) E.B.Knox; for this article, Senecio stanleyi was considered to be a synonym of Dendrosenecio adnivalis.