© 2001-2024 by Robert J. Baran
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THE OTHER PORTULACARIA Portulacaria armiana E.J. van Jaarsveld The whip-stick pork bush is a rounded evergreen succulent shrub of 50 to 70 cm in height when not in flower and 70 cm to 1 m wide. Branches are short, terete and thick, up to 3.5 cm in diameter. They bear conspicuous leaf scars. Young branches are softly succulent and gray-green, 0.9 to 1.2 cm in diameter with internodes 1.0 to 3.0 cm apart. Older branches are woody, yellow-brown with bark peeling characteristically in horizontal, tough and slightly translucent papery flakes. Leaves are fleshy, decussate, glaucous, obovate-ovate, 3.0 to 7.0 cm x 3.0 to 5.5 cm. The base is cuneate, with a 2 to 5 mm long short petiole. The apex is rounded, and the margin is slightly wavy. A single whip-stick like flowering branch is terminal, erect and 3 to 5 m long, sparingly branched, herbaceous and snapping when bent. Bracts are leaf-like but smaller, 3.0 x 1.4 cm, often muconate and soon deciduous, with internodes 2 to 10 mm apart. Inflorescences are borne laterally from the axils, 5.0 to 10.0 cm long. Flowers in dense fascicles (up to 10): pedicels 1, 5 mm. Sepals 2, broadly ovate and acute, 5 mm long: receptacle conical, 1 mm wide. Petals 5, 2.5 to 3 mm long, oblong and white, free to the base, hooded and obtuse at the pex. Stamens 0.75 to 1 mm long, often aborted, (adnate to the) petals: pistil flask-shaped, 2 mm long, style branches 3, spreading; ovary obscurely 3-angled, approximately 1 mm in length. Flowering period is from July through October.
Portulacaria armiana van Jaarsveld, sp. nov. Inflorescence showing b: bracts; s: stem (life-size).
(Illustration by Jeanette Loedolff as Fig. 1 on pg. 394 of Van Jaarsveld.) P. arminiana occurs in a very dry and remote part of the lower Gariep river valley in Namaqualand Broken Veld. It is as yet only known from a single locality approximately 3 km north of Sandberg (northern Richtersveld/southern Namib) but it may be more widespread in adjacent areas. At this arid, desolate and inhospitable locale under 500 meters altitude, rainfall is very low. Precipitation, which mainly occurs in winter, ranges from 2.5 to 3.0 cm per annum, although in some years no rain may fall. This spreading succulent shrub is a conspicuous feature of the north-facing mica-schist koppies and the plants found are scattered amongst rocks.
This new species is named after Mr. A. R. Mitchell, a botanist and natural explorer specializing in succulents, who
first came across this species. He noticed this strange "
Crassula
" with the tall flowering branch and later brought it to the attention of van Jaarsveld. In 1983 an expedition
was arranged to investigate the discovery, and the plant was first officially described in early 1984.
The plant has more recently (2003)
been described as "the extremely rare botanical curiosity, Portulacaria armiana, a succulent shrub
which grows an inflorescence 4 meters tall." * * * * * * * P. pygmaea Pillans This dwarf species occurs far less commonly than P. afra in Namaqualand and southern South West Africa. The plants are compact, up to 20 cm tall and 30 cm in diameter, forming mounds on hilly slopes. The thick, sessile leaves (10-14 mm long, 7-9 mm across) are bluish-green. The small, inconspicuous flowers are pale pink, usually in terminal clusters of two to six. With thick tuberous water-storing rootstocks, these plants are found in hot arid regions of the northern Richtersveld and across the Orange River to south of Luderitz. Also known as Ceraria pygmaea. |
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THE FALSE PORTULACARIA P. namaquensis (Sond.) = Ceraria namaquensis. Habitat: Namaqualand. Described prior to 1862. This plant grows 1.3 to 1.7 m high. Branches are greyish-green and dichotomous, the ultimate as thick as a goose-quill. Leaves are 4 mm long, minute, sessile. Peduncles 13-17 mm long, angular, unbranched. Pedicels involucrated by some minute ovate bracts, about 4 mm long, solitary or few. Calyx 2-phyllous, three times shorter than the 5 rose-colored, obovate, near 2 mm long petals. Stamens 5; filaments linear. Anthers oblong, emarginate at both ends. Ovary ovate. Style short.
Per Rauh (pg. 133),
Ceraria namaquensis
grows well when grafted to
P. afra
and propagation of
C. pygmaea
is easy by grafting onto
P. afra.
For this reason, some botanists have labelled these
Ceraria
as two additional
Portulacaria
species.
Per the
National Botanical Institute, South Africa
website, P. afra is also used as a rootstock for grafting the closely related but more difficult
to grow Namaqua porkbush, Portulacaria armiana (previously Ceraria namaquensis), which cannot
tolerate water around its roots as it comes from very dry areas. See the "Cultivation and Propagation"
of this
article.
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BIBLIOGRAPHY
International Succulent Congress,
<<
Pre-congress field trip to SOUTHERN NAMIBIA &
RICHTERSVELD>> (18 -28 September 2003),
http://www.succulents.net/succulenta2003/pre_congress.html
Namaqualand and Richterveld sections of the National Botanical Institute http://www.nbi.ac.za/kirstenbosch/conservatory/namaqua.html Court, Doreen Succulent flora of Southern Africa ; Rotterdam: A.A. Balkema; 1981. Pp. 109-110. Killick, D.J.B. (ed.) The Flowering Plants of Africa, Botanical Research Institute, Dept. of Agricultural Technical Services, 45:1763. Medley Wood, J. and Maurice S. Evans Natal Plants ; Durban: under the Auspices of the Natal Government and Durban Botanic Society; 1899. Vol. 1. Pg. 64. Rauh, Werner The Wonderful World of Succulents ; Washington, D.C.: Smithsonian Institution Press; 1984. Translated by Harvey L. Kendall. Pg. 134. Ross, J.H. Flora of Natal, Pretoria: Dept. of Agricultural Technical Services; 1972. Pg. 164. Sim, Thomas R. The Forests and Forest Flora of The Colony of the Cape of Good Hope ; Aberdeen, Scotland: under the Authority of the Government of the Cape of Good Hope; 1907. Pg. 134. Sonder, Otto Wilhelm Flora Capensis ; London: Lovell Reeve & Co.; 1862. Vol. 2. Pp. 385-386.
Van Jaarsveld, E.J.
"Portulacaria armiana,
a new
Portulacaria
from southern Namibia,"
Journal of South African Botany, 1984. 50:393-399. The primary
source of the above
description, a copy of this article was kindly provided to RJB by C. L.
Bredenkamp of the National Botanical Institute of South Africa, Pretoria.
References Not Yet Checked include the following:
"Portulacaria armiana 18S ribosomal RNA gene,
partial sequence; internal transcribed spacer 1, 5.8S ribosomal RNA gene and internal transcribed spacer 2, complete sequence; and 26S
ribosomal RNA gene, partial sequence," National Center for Biotechnology Information.
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If you have comments or thoughts concerning this, please e-mail me, rjb@magiminiland.org |