EEINWARDTIA

Published by Herbarium Bogoriense, Kebun Raya Indonesia
Volume 1, Part 1, pp. 27-31 (1950)

FURTHER NOTES ON THE FERN-GENUS HETEROGONIUM PRESL

R. E. HOLTTUM *

In the "Sarawak Museum Journal," volume V (1949), pages 156-166,
I gave a revised account of the genus Heterogonium Presl, based on spec-
imens in the Singapore herbarium. Dr M. A. Donk wrote subsequently
pointing out that specimens at Bogor (Buitenzorg) add materially to the
information contained in that paper. The present paper gives the result
of a study of the Bogor specimens. I am glad to express my gratitude
to Dr Donk for calling my attention to species which I had overlooked
when searching literature on Malaysian ferns for indications of affinity
to Heterogonium.

The Bogor material includes the type specimens of Acrostichum
teysmannianum Bak., Phegopteris schizoloma v. A. v. R., Dryopteris sa-
genoides forma contracta v. A. v. R., Polybotrya nieuwenhuisii Racib. and
Polybotrya nieuwenhuisii var. brooksii v. A. v. R., also many sheets of
H. giganteum, and material of H. sagenoides from a wider geographic
range than I had previously seen.

Summarizing the results of the present paper, I have united H.
nieuwenhuisii and H. stenosemioides of my former paper, and have also
united H. saxicola with H. giganteum. Further, I now recognize a second
exindusiate species allied to H. sagenoides; but the variation in pubes-
cence among exindusiate specimens, as within the species H. sagenoides
proper, is very considerable, and I find it very difficult to draw specific
limits. It is likely that there are local races, but much more field work
in many localities is necessary before one can speak with certainty about
this or define their status taxonomically. One interesting fact is that no
exindusiate specimens of this alliance have been found in the Malay
Peninsula, whereas Peninsular collections of indusiate H. sagenoides are
more abundant than from any other area. It is especially the variation
in pubescence among specimens of H. sagenoides, and the lack of clear-cut
varieties or subspecies within the Malay Peninsula, that deters me from
distinguishing more species outside the Peninsula, based on few spec-
imens. Another generalization based on many specimens is that fertile
fronds are always much less hairy on the lower surface than sterile fronds
of the same plant. As regards another kind of character, namely venation,
I have noted that fronds of immature plants may not show the low

* Professor of Botany, University of Malaya, Singapore.

— 27 —



28 feBtswAftDTiA [VOL. l

attachment of the basiscopic veinlets characteristic of this genus and
Tectaria.

REVISED KEY TO THE SPECIES OF HETEROGONIUM

1. Veins free
2. Sori indusiate 1- H- sagenoides

3. Lower surface of veins and costules hairy; sterile pinnae lobed to 2—3
mm from costa typical form

3. Lower surface of veins and costules glabrous; sterile pinnae lobed to
4—5 mm from costa forma contracta

2. Sori without indusia
4. Fertile pinnae not acrostichoid; sori separate from each other

2. H. teysmannianum
4. Fertile pinnae acrostichoid, or at least some sori confluent

5. Fronds to at least 70 by 30 cm 2. H. teysmannianum
5. Fronds not over 25 cm long 3. H. stenosemioides

1, Veins anastomosing
6. Fertile fronds acrostichoid or subacrostiehoid

7. Sori indusiate ' . , . 4. H. alderwereltii
7. Sori not indusiate 5. H. pinnatum

6. Fertile fronds with distinctly separate sori which do not almost or entirely
cover the lower surface
8. Sori elongate, exindusiate

9. Veins anastomosing in costal and costular arches only
6. H. aspidioides

9 . V e i n s m o r e c o p i o u s l y a n a s t o m o s i n g . . . . . 7 . H . profereoides
8 . S o r i r o u n d , r a t h e r l a r g e , o r o n l y s l i g h t l y e l o n g a t e , a p p a r e n t l y s o m e t i m e s

i n d u s i a t e 8. H. giganteum
1. H, SAGENOIDES (Mett.) Holtt. in Saraw. Mus. Journ. 5: 161. 1949.

This species is very variable in the shape of its pinna-lobes, and
somewhat in its hairiness, even among plants growing in the same locality.
Fertile fronds are always much less hairy than sterile. Sterile fronds
have scattered hairs on the upper surface, sometimes also with numerous
shorter papillae, and the costae are densely hairy; the lower surface nor-
mally has longer slender hairs on costae, costules and veins only, but
specimens from Ginting Simpah (S.F.N. 31192, Holttum) have very finely
hairy surfaces between the veins, in sterile fronds only.

Forma contracta v. A. v. R. in Bull. Buitenz. Ser. Ill, 2: 147. 1920.
Differs from the typical form of the species as follows: pinnae of

sterile fronds lobed to 4—5 mm from the costa, the lobes commonly 5 mm
wide; lobes of fertile pinnae about 2.5 mm wide, widely spaced; lower
surface, veins and costules of sterile pinnae quite glabrous, costae bearing
sparse very short hairs only, upper surface of costae bearing copious
very short hairs, surface glabrous except for a small group of very short
hairs at each sinus.

DISTRIBUTION. — Only known from Sibolangit in Sumatra (between Medan
and Brastagi) ; the specimens are remarkably uniform.

Lorzing 5520, 5529, 6339 (all Herb. Bog.) ; S.F.N. 6iU (Md Nnr).

1950] BOLTTUM; Notes on Heterogonium

If this proves as distinct as these specimens indicate, it may rank
as a distinct species, or at least as a distinct variety of H. sagenoides.
Pending further information about the latter species in Sumatra how-
ever, it seems preferable not to propose a new name or new status for
these specimens.

2. H. teysmannianum (Bak.) Posthumus (MS in Herb. Bog.), comb. nov.
Basinym: Acrostichum teysmannianum Bak. in Malesia 3: 56. 1886.
Polypodium obscurum Hook., Sp. Fil. 4: 237. 1862 (not P. obscurum Mett. 1857).

— Phegopteris obscura Chr. in Bull. Herb. Boiss. 6: 196 t. 5. 1898.
Acrostichum teysmannianum Bak. in Malesia 3: 56. 1886. — Stenosemia teys-

mannianum Diels in Eng. & Pr., Nat. Pflanzenfam. 1/4: 198. 1899.
Phegopteris schizoloma v. A. v. R. in Bull. Buitenz. Ser. II, 16: 24. 1914.
IPolybotrya nieuwenhuisii var. brooksii v. A. v. R. in Bull. Buitenz. Ser. II,

23: 19. 1916.

The type collection of this species, made by Teysmann in Sumba, is
a rather large fern, with sterile fronds (excluding stipes) some 70 cm long
and 30 cm wide, the middle sterile pinnae rather more than 3 cm wide
and lobed to 2 mm from the costa with lobes 4—5 mm wide, the lobes of
fertile pinnae about 12 mm long and 2 mm wide, completely covered be-
neath with sporangia; the pubescence is slight, about as in H. sagenoides
forma contracta. From the island of Sumba also is a collection by Iboet
(no. 314) with fronds somewhat smaller in all parts and the sori mostly
separate, not acrostichoid; the pubescence is like that of the type.

The type of Phegopteris schizoloma (northern part of S.E. Borneo,
Bukit Sungai Tempilan, Amdjah 595) is very similar in all respects to
Iboet 314 except that it is slightly hairy all over the lower surfaces, with
fairly long hairs in costae and costules; the sori are mostly separate but
the distal ones on some lobes coalesce to a subacrostiehoid condition.

Polybotrya nieuwenhuisii var. brooksii v. A. v. R. (Bencoolen, Brooks
195/S) from South Sumatra is similar in general aspect to the type of
P. schizoloma, but is nearer a fully acrostichoid condition, with rather
longer hairs on costae and costules of the lower surface of sterile fronds
but no hairs on the upper surface.

The type of Polypodium obscurum Hook, (as figured in Hook. &
Bauer, Gen. Fil. t. 9U, fig. 5, 6) had quite separate sori, but evidently
did not differ in frond form from all the above; the specimen came from
Leyte (Cuming 302, not seen).

In view of the lack of sharply distinguishing characters between the
above specimens, I think it best to unite them, and the oldest epithet
which can be used is "teysmannianum." I have provisionally kept H. ste-
nosemioides separate, though perhaps further collections will show inter-
mediates between it and the specimens above discussed; possibly Poly-
botrya nieuwenhuisii var. brooksii is such an intermediate.



R E I N W A R D T I A [VOL. 1

8. H. STENOSEMIOIDES (Bak.) C. Chr.; Holtt. in Saraw. Mus. Journ. 5: 161.
1949.
H. nieuwenhuisii (Racib.) C. Chr.; Holtt., I.e.

The type collection of Baker's species is not at Singapore, but we
have a specimen from the type locality (Mt Matang) by E. S. Hose, and
one from Mt Gading collected by Bishop Hose and labelled "stenosemioides
n. sp." The Matang specimen has rather many scattered hairs on the
upper surface, the (smaller) Gading specimen has few, but they are not
confined to the sinuses, and I see no other difference. Kloss's specimen
from Bettotan (see below) is closely similar to that from Matang.

The type of H. nieuwenhuisii was a plant cultivated at Bogor (Bui-
tenzorg), brought from Borneo by Nieuwenhuis. The type specimen shows
only quite small fronds (including fertile ones). Later specimens taken
from the same plant have larger fronds, and are closely similar to the
specimens of H. stenosemioides above mentioned, but the upper surfaces
have no hairs except near the sinuses. The specimens collected by Amdjah,
referred to this species at Bogor, are sparsely hairy on the upper surface,
and Winkler's specimen is more hairy. It seems therefore that in this
species hairiness of the upper surface is variable; and in any case such
hairiness does not constitute a difference between H. stenosemioides and
H. nieuwenhuisii. As noted under H. teysmannianum, var. brooksii may
be an intermediate bridging the gap between H. teysmannianum and H.
stenosemioides.

BORNEO: C u l t . H. B o t. B o g . 2 K. XIII. 2: Nieuwenhius (several specimens);
northern p a r t of S. E. B o r n e o : Bukit Sungai Tempilan, Amdjah 576; Bukit Ulu
Sebulu, Amdjah 414; between Kundim Baru and Batu Bali, Hubert Winkler 2761;
B r i t i s h N o r t h B o r n e o : near Sandakan, Kloss s.n.

4. H. ALDERWERELTII Holtt. in Saraw. Mus. Journ. 5: 163. 1949.
I have now examined the type of Pleocnemia stenosemioides v.A.v.R.,

on which this species was based. The sori are indusiate, in which the
specimen differs from H. pinnatum, but the specimen is smaller than the
Peninsular specimens upon which my description was based. I still think
this is a good species, but one ought to get specimens and grow them side
by side with H. pinnatum.

5, 6, 7. H. PINNATUM, H. ASPIDIOIDES and H. PROFEREOIDES.
The Bogor (Buitenzorg) specimens add no significant information

concerning these species.

8. H. GIGANTEUM (Bl.) Holtt. in Saraw. Mus. Journ. 5: 166. 1949.
H. saxieola (Bl.) Holtt., I.e., with synonyms.
There are ten collections of this species in the Bogor (Buitenzorg)

herbarium; in three of these there are indications of the presence of in-

1950] HOLTTUM: Notes on Heterogonium 31

dusia, but in no case are the indusia well preserved. Apart from the in-
dusia, I can see no clear distinction between these and the other specimens
referred to H. giganteum; variation occurs in the shape and lobing of
pinna-lobes among exindusiate specimens and does not appear to me
significant. I therefore include all under the epithet "giganteum" (Backer
and Posthumus have united the species and prefer this epithet; the two
names Aspidium giganteum and A. saxieola were simultaneously publish-
ed).

Specimens from outside Java at Bogor are: CERAM: Rutten 2210 (this has
very large sori). — CELEBES: S. W. Celebes, Lambasing, Biinnemeijer 11171.

DOUBTFUL SPECIMENS. — Two small specimens are not clearly referable
to any of the above species, and might represent new species. I believe
however that the specimens, though partly fertile, are immature as
regards size, and it therefore seems undesirable to use them as types for
the description of new species. The Celebes specimen has the lowest
basiscopic veinlets borne above the bases of the costae, but (as above
noted) I think this may be a juvenile character.

The specimens are: CELEBES: S. Celebes, between Makassar and Maros, van
Steenis 10432. — PHILIPPINES: Luzon, Irosin, Prov. Sorsogon, Elmer 17230.


	Binder2
	Rein.Vol 1,Part 1, pp 1-66_Page_01
	Rein.Vol 1,Part 1, pp 1-66_Page_15
	Rein.Vol 1,Part 1, pp 1-66_Page_16
	Rein.Vol 1,Part 1, pp 1-66_Page_17