A revision of Lebeckia sect. Lebeckia: The L. sepiaria group
Author
le Roux, M. M.
Department of Botany and Plant Biotechnology, University of Johannesburg, P. O. Box 524, Auckland Park 2006, South Africa
Author
Van Wyk, B. - E.
Department of Botany and Plant Biotechnology, University of Johannesburg, P. O. Box 524, Auckland Park 2006, South Africa
bevw@na.rau.ac.za
text
South African Journal of Botany
2007
2007-01-31
73
1
118
130
http://dx.doi.org/10.1016/j.sajb.2006.09.005
journal article
10.1016/j.sajb.2006.09.005
3a3b284a-51fc-46db-b751-28978c8e5adf
7958313
3.2. The section
Lebeckia
Lebeckia
Thunb. section
Lebeckia
.
Type
:
L. sepiaria
(L.) Thunb., chosen by Hutchinson in Gen. Flow.
Pl.: 358 (1964)
.
Spartium
L.
,
Pl. Rar. Afr.: 91 (1760)
, Sp.
Pl.: 995 (1764)
,
Gmelin,
Syst. Nat. 2 (2): 1088 (1792)
,
pro parte
.
Lebeckia
Thunb., Prod. Pl. Cap.
: 122 (1800)
, Fl. Cap.: 561 (1823),
pro parte majore
;
Eckl
. and
Zeyh
., Enum.: 192 (1836)
,
pro parte majore
;
E. Mey. in
Linnaea 7: 155 (1832)
,
Comm. Pl. Afr. Austr. 1: 34 (1836)
,
pro parte majore
.
Sarcophyllum
E. Mey.
in
Linnaea 7: 155 (1832)
,
Comm. Pl. Afr. Austr. 1: 34 (1836)
.
Eu-Lebeckia
Benth. in
Hook.,
Lond. J. Bot. 3: 358 (1844)
,
synon. nov.
Phyllodiastrum
Benth. in
Hook.,
Lond. J. Bot. 3: 358 (1844)
,
synon. nov.
Erect to prostrate, slightly to markedly glaucous suffrutices.
Leaves
simple, acicular, glabrous, sparse or dense, spirally arranged, often articulated near the middle, mucronulate.
Inflorescences
terminal, short or elongate, laxly to densely manyflowered; rachis usually furrowed; flowers small or large (
6– 18 mm
long), yellow; bracts ovate to lanceolate, acuminate, caducous; bracteoles narrowly triangular, acuminate.
Calyx
equally to subequally lobed, lobes deltoid, ± as long as the tube, tips minutely pubescent on the inside.
Petals
yellow, sometimes fading to orange or rarely purple (
L. longipes
), invariably totally glabrous.
Standard
lanceolate to orbicular; apex obtuse.
Wings
oblong; apex obtuse; sculpturing present or absent.
Keel
rostrate, pockets sometimes present.
Stamens
fused into an open sheath, upper third free; anthers 10, 5 oblong and basifixed, 5 short and dorsifixed (vexillary stamen only slightly shorter than long anthers).
Pistil
sessile to markedly stipitate; ovary oblong to linear; ovules ± 6–20; style shorter than the ovary, curved upwards.
Pods
linear or ovoid, straight or slightly deflexed, up to
12 mm
wide.
Seeds
reniform.
3.2.1. Diagnostic characters
Species of
Lebeckia
section
Lebeckia
differ from all other species in the genus by their needle-like leaves, which are terete (never flat).
3.2.2. Distribution
Lebeckia
section
Lebeckia
(and also the
L. sepiaria
group) are endemic to the Cape Floristic Region, from Namaqualand to Port Elizabeth.
Key to the species of
Lebeckia
section
Lebeckia
1a. Keel spirally twisted:
2a. Fruit up to
50 mm
long; short-lived fireweed;
L. wrightii
flowers 1–3 per inflorescence
2b. Fruit
60–120 mm
long; perennial herb;
L. pauciflora
flowers more than 5 per inflorescence
1b. Keel not twisted:
3a. Calyx teeth longer than the tube
L. grandiflora
3b. Calyx teeth shorter than the tube:
4a. Leaves articulated near the middle:
5a. Fruit long-stipitate (stipe
10–20 mm
long);
L. carnosa
flowers very widely spaced on rachis
5b. Fruit sessile or short-stipitate (stipe less than
5 mm
long), flowers usually densely spaced on rachis
(if somewhat widely spaced, then the fruit is flat):
6a. Fruit ovoid (up to
13 mm
long)
L. brevicarpa
6b. Fruit oblong to linear (more than
15 mm
long):
(continued on next page)
7a. Fruit oblong (up to
6x
longer than wide), flat, upper suture with distinct margin or wing:
8a. Flowers
6–11 mm
long;
L. meyeriana
fruit
20–35 mm
long
8b. Flowers ca.
15 mm
long;
L. macowanii
fruit ±
50 mm
long
7b. Fruit linear (more than 10× longer than wide), terete or semi-terete, upper suture without a margin or wing:
9a. Flowers usually up to
8 mm
long;
L. gracilis
upper lateral sinuses of calyx± as wide as medial sinus and lower lateral sinuses; southern coastal distribution from Bredasdorp to Port Elizabeth
9b. Flowers more than
9 mm
long; upper lateral sinuses of calyx much wider than medial sinus and lower lateral sinuses; western coastal distribution from Namaqualand and inland to the Cedarberg and eastwards to Heidelberg:
10a. Fruit dehiscent, not spongy, subterete,
L. ambigua
±
2 mm
wide, sometimes falcate
10b. Fruit indehiscent, spongy, terete,
L. sepiaria
more than
4 mm
wide, straight, often somewhat torulose
4b. Leaves not articulated:
11a. Fruit long-stipitate (stipe
15 mm
or longer)
L. longipes
11b. Fruit sessile or short-stipitate
L. plukenetiana
(stipe up to
5 mm
long)
Within the section
Lebeckia
, there are four species groups:
(1) the
L. sepiaria
group — four species with terete or semi-terete, ± sessile pods and a generally erect, virgate habit (
Fig. 1
).
(2) the
L. plukenetiana
E. Mey.
group — five species with stipitate, flat pods of up to
75 mm
long.
(3) the
L. wrightii
(Harv.) Bolus
group – one species – a short-lived fireweed with stipules and flat pods.
(4) the
L. pauciflora
group — two species with relatively long calyx lobes and linear, stipitate, semi-terete pods of more than
70 mm
long.