|The Cycad Pages
- Cycas circinalis L., Sp. Pl.: 1188 (1753).
- "TYPE: the illustration: Rheede, Hort. Malab., t. 19, 1682 (lecto, fide Stevenson in Jarvis et al.)."
Cycas circinalis var. angustifolia Miq., Comm. Phyt.: 125-126 (1840-1841).
- "TYPE: ex hort. bot. Calcutta, U 028096 (lecto U). *De Laub says P?"
- [Cycas circinalis subsp. vera J. Schust., "Pflanzenr. 99: 66-67, Fig. 40; 7C; 10A, F-G; 11F" (1932), nom. nud.]
- [Cycas circinalis var. swamyii D.D. Pant, Cycad Newsletter 23(1): 6 (2000), nom. nud.]
From the Latin circinus, a spiral, in reference to the
inrolled leaflets in developing leaves.
Ho & Duong 1960,
Raizada & Sahni 1960,
Zamora & Co 1986,
Bot. Mag. 1828
(and as C. jenkinsiana),
(and as C. rumphii ssp. zeylanica),
Zamora & Co 1986
Surrounded by confusion since its inception, this was described
as the single constituent species when the great Swedish botanist
Carolus Linnaeus established the genus Cycas in 1753. He had,
however, based his description on a number
of earlier works that in fact covered at least three distinct
species as we now know them. The subsequent history of this name
has been one of total confusion. C. circinalis has subsequently
appeared in the literature more frequently than any
other Cycas combination, arguably without a single author wholly
correctly applying the name.
Of the eight references cited by Linnaeus, only two refer to C.
circinalis as now typified. This reflects an increasing understanding
of the systematics of the group since the time of Linnaeus' work.
The other species covered by Linnaeus' description are now known
as C. revoluta, separated by
Thunberg in 1784,
and C. rumphii, separated by
1839. The latter is part of
a widespread species complex, all of which have been treated as
part of C. circinalis at some time or other.
Although well known in Indian culture for many centuries
1682), the first reference to this species in Western writings
was in Rheede's Hortus Malabaricus, published in Amsterdam
in 1682. Although this publication has generally been accepted
as the basis for this species
1868: 525, Stapf 1916,
it was not formally
designated the type until
1993 (Jarvis et al.).
Much of the confusion associated with this species arises from
the difficulty in recognising Miquel's segregate species C.
rumphii, and its full geographic extent. Miquel himself had
difficulty recognising the limits of these taxa
(1868), and often
changed his mind (see C. rumphii). Characteristics by which
these species can be recognised were also not well known. The
difficulty in separating the two has continued to the present
(eg. Jones 1993), and has severely
reduced the usefulness and
value of a number of anatomical and morphological studies based
on unvouchered or cultivated materials (eg. Dehgan & Yuen
1983, Pant 1993). Almost all plants in
cultivation that have been
known as C. circinalis in fact belong to the C. rumphii
complex. The name C. circinalis has also been applied uncritically
to local in many parts of the world, without real knowledge of
the true nature of typical C. circinalis. Examples of misapplication
occur in Ceylon (Trimen 1898 - C. nathorstii), Thailand
(Suvatabandhu 1961, Smitinand 1971, 1972 - C. spp.), Malaysia
( Gibbs 1914 - C. rumphii), The
Philippines ( Amoroso 1986,
Zamora & Co 1986 - C. riuminiana), New
Guinea (Borrell 1986 -
C. apoa; Paijmans 1986 - C.
White 1922 - C. scratchleyana) and
the western Pacific (Burkill 1901,
de Laubenfels 1978,
Yuncker 1959 - C. seemannii;
Fosberg & Sachet 1975,
Stone 1970 - C. micronesica).
In the protologue of C. circinalis, Linnaeus (1753, 1754)
cited treatments of Cycas from eight earlier works, including at least three taxa
as they are currently circumscribed, but also stated 'Habitat
in India'. Stapf (1916) stated '... the C. circinalis of
India represented by Rheede's Todda Panna (Rheede 1682:
9, tab. 13-21), the accepted basis of Linnaeus's species.' Lectotypification
was discussed but not formally designated by Wijnands (1986).
No specimens relating to Hortus Malabaricus are known, and one
of the series of illustrations of Todda Panna by Rheede
(tab. 19) has since been designated the lectotype by Stevenson
in Jarvis et al. (1993).
Characterised by a non-pectinate megasporophyll with subglobular
seeds that display a distinctive fibrous layer within the sarcotesta,
and an attenuate microsporophyll apex. This megasporophyll morphology
occurs in many other species, and largely the cause of much of the confusion.
The attenuate microsporophyll state is, however, restricted to
a few species from the Indian subcontinent, as is the fibrous
layer within the sarcotesta. This fibrous layer is a distinct
advanced evolutionary character found in all species of the
Indian subcontinent, and also in the C. pectinata group and
in a number of upland forest species occurring throughout
Distribution and habitat:
C. circinalis is now known to be an Indian endemic, restricted
to the Western Ghats, in the states of Kerala, Karnataka, Tamil
Nadu, and the south of Maharashtra. It typically occurs in fairly
dense, seasonally dry scrubby woodlands in hilly areas. Many trees
in this habitat lose their leaves in the dry season, and C.
circinalis is also facultatively deciduous in extremely
The taxon from the northern
Eastern Ghats in the state of Orissa, described as C. circinalis
var. orixensis by
and generally treated as
C. circinalis, differs
markedly in its megasporophylls. It in fact represents a
separate species (see C. spherica).
Locally abundant in several areas, although the habitat has been
severely reduced and degraded. Good populations still exist in
a number of forests reserves.
Stems arborescent, to 5 m tall.
Leaves bright green, semiglossy, 150-250 cm long, flat (not keeled) in section (opposing leaflets inserted at 180° on rachis), with 170 leaflets, tomentum shedding as leaf expands. Petiole 40-70 cm long, glabrous, spinescent for 90% of length. Basal leaflets not gradually reducing to spines.
Median leaflets simple, weakly discolorous, 150-300 mm long, 7-12 mm wide, narrowed to 2.5 mm at base, 12 mm apart on rachis; median leaflets section flat; margins flat; apex softly acuminate, not spinescent; midrib raised above, flat below.
Cataphylls narrowly triangular, soft, thinly sericeous or lacking tomentum, 50 mm long, persistent.
Pollen cones narrowly ovoid, orange, 45 cm long, 10 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 38-50 mm long, 12-19 mm wide, apical spine prominent, gradually raised, 25 mm long.
Megasporophylls 30 cm long, brown-tomentose; ovules 4-10, glabrous; lamina lanceolate, 74-100 mm long, 25-38 mm wide, regularly dentate, with 24 pungent lateral spines, apical spine distinct from lateral spines.
Seeds subglobose, 25-38 mm long; sarcotesta yellow; fibrous layer present; sclerotesta smooth. Spongy endocarp absent.