Heteroscyphus grandiflorus (Steph.) Hürl.

Thouvenot, Louis, 2023, A taxonomic revision of the Lophocoleaceae Vanden Berghen (Marchantiophyta) of New Caledonia, Cryptogamie, Bryologie 20 (1), pp. 1-60 : 28-30

Heteroscyphus grandiflorus (Steph.) Hürl.

( Fig. 15 )

Bauhinia 12: 114 ( Hürlimann 1998). — Chiloscyphus grandiflorus Steph. , Species Hepaticarum 6: 307 ( Stephani 1922).

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Type: New Caledonia. Lerat s.n. (lecto-, here designated, G [“Original”, Lerat 265-03, G00069506 ]!; syn-, G [ Pic des Sources , “moitié”, Le Rat 259, G00283070 !, Mt. Mou , VII.1909, Le Rat 133, G00283071 ]!; isosyn-, REN [ Mt. Mou , VII.1909, Le Rat s.n., herb. E. G. Paris]!).

Chiloscyphus grandiflorus var. latifolius Herzog, Arkiv för Botanik, n.s. 3 (3): 49 ( Herzog 1953).

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Type: New Caledonia. N.branch of Yaté River , 400 m., 8.VII.1949, Selling B12 (holo-, S) syn. nov.

Chiloscyphus quadricilius Steph. , Species Hepaticarum 6: 312 ( Stephani 1922).

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Type: N ew Caledonia. “ Lerat ” s.n. (lecto-, here designated, G [“Nova Caledonia”, s.l., s.d., Lerat 21, G 00283105 ]!) syn. nov.

FURTHER SPECIMENS EXAMINED. — New Caledonia. North Province, Poindimié, Tango plateau , Napapwa , on the ground in rain forest, 467 m, 20.IX.2019, Thouvenot NC2895; South Province, Bouloupari, Mt. Do , on peridotite rocks in cloud forest, 995 m, 25.X.2012, Thouvenot NC752; Paita, Dzumac massif , on rocks in mesophilous forest, 915 m, 18.IX.2008, Thouvenot NC331; Yaté, Nooti , on laterite rock, in photo-xerophyte forest, 443 m, 5.X.2019, Thouvenot NC2750; Yaté road, col des deux Tétons , 24.VII. 2014, Métoyer NC1686 ( NOU); MET027 ( NOU); Yaté road, col des deux Tétons , 3.XII.2014, Métoyer NC1687 ( NOU); NC1688 ( NOU); MET055 ( NOU); MET056 ( NOU).

DISTRIBUTION IN NEW CALEDONIA. — One of the most frequent species of Lophocoleaceae in both provinces of Grande Terre, Heteroscyphus grandiflorus grows in usually wet conditions on the ground where it occupies a range of substrates, including bare soil, humus, plant debris, dead wood, rock, etc. at low to medium elevations (collected from sea level to 1000 m).

TOTAL RANGE. — Endemic.

DESCRIPTION

Dioecious.

Habit

Variable (see comments); plants medium to large, light green to red-brown or olive-brown, wet shoots 2.00-4.00(-5.00) mm wide, leaves subopposite, densely imbricate, dorsally free, when dry dorsally concave to canaliculate, patent at 60-90° angle.

Leaves

The most typical leaves are 1.00-2.00 mm long, 0.80-2.00 mm wide at base, widely oval-ovate, apices rounded to widely triangular, usually with 3 long cilia made of 3-6 uniseriate elongate cells narrower from base to tip, ventral margins with 0-3(-4) cilia identical to the apical ones.

Cells

Leaf cells 37-65 µm long, 32-42 µm wide, trigones medium to large, rounded to truncate.

Underleaves

Connate with the ventral bases of both nearest leaves, the most typical underleaves transversely elongate, 2-4 times wider than the stem, discs 0.35-0.50 mm high, 0.60-1.00 mm wide, apices bifid-quadrifid, sinus lunate, lobes narrowly linear lanceolate, single or furcate, lateral margins with one to several long narrow teeth sometimes furcate, at most the entire margins appearing laciniate all around, minor forms with only four apical teeth or two apical and one small marginal on both sides.

Gametangia

On short lateral-intercalary branches lacking normal vegetative leaves, rarely with one pair of small vegetative leaves at base; gynoecia with bracts large, lobate-laciniate, bracteoles smaller, deeply bifid and laciniate; perianths cyathiform, 3.00 mm long, 2.00 mm wide, deeply lobate-laciniate at mouth; androecia in short spikes, 0.40 mm long, with 2-5 pairs of bracts cochleariform-canaliculate, toothed-ciliate, bracteoles shortly bifid with a few unicellular teeth, antheridium stalk three ranked.

COMMENTS

As underlined for many species of the genus, this frequent species has variable looks, mainly in leaf and underleaf orna-mentations, even in the same plant, so that some specimens might be thought to belong to different species or distinct varieties. Usually, main shoots have the largest leaves, with many cilia around the margins and underleaves with two apical lobes often furcate and lateral margins lobate ciliate, whereas, on the secondary branches, leaf margins may be naked except the apical three cilia and underleaf cilia may be simple; minimal forms of underleaves have only two apical cilia and one short cilia on both margins. But, in all observed specimens, the overall leaf shape and areolation are constant despite the size and ornamentation diversity, except the single sample from semi-aquatic habitat with oblong-oval leaves, usually biciliate leaf apices, olive brown colour (Thouvenot NC2894). Other characters varying case to case are colour, from light green to red brown or olive green, leaf cell trigones truncate to rounded, underleaf cell trigones which may be like the leaf ones to nearly absent. The well-developed populations include usually a large morphological variability. But we are often faced with quite homogeneous populations with a peculiar set of characteristics raising the question of the variety status . Notably, the variety latifolius defined by Herzog from differences in leaf size and number of leaf segments falls in synonymy to the typical forms since such characters can be observed in some shoots of the types kept at G: the observed variability in the leaf base width ranges from 0.70 to 1.00 mm and ornamentation from 3 to 8 fringe segments. This is a frequent character in Lophocoleaceae where secondary shoots and ultimate branches exhibit less process numbers and smaller sizes than primary stems. Old primary parts may be destroyed or broken and inconspicuous in some type specimen so that it could give rise to different diagnoses. At the other end, populations might be gathered into a variety “ minor ” when the following forms of morphological characters are evenly expressed: leaves without marginal processes except the three, rarely two, apical ones, underleaves of the less developed type, hardly twice as wide as the stem, 2-4-fid, lobes short linear, one short tooth on both margins (e.g. Metoyer NC1687, Thouvenot NC2895). Some were collected in peculiar habitats, namely very shaded, semi-aquatics or disturbed habitats. In the latter cases, the author hypothesise they could be mats of secondary shoots regenerating from broken stems, since it was sometimes possible to find a few old shoot segments with typical wide laciniate underleaves.

Among the two type specimens of Chiloscyphus quadricilius kept at G, only number G00283105 matches the Stephani’s protologue and, therefore, is selected as the lectotype. The selection of the specimen G00069435 “sur les arbres, 1905, Le Rat 302 ” as a type specimen of C. quadricilius fide Bonner (1963: 767) is not supported by the observation of its morphological characters since leaf apices are widely rounded with four small apiculate teeth at leaf apices and small bifid underleaves with only one marginal tooth on both margins, so that it differs highly from the diagnose and drawing of Stephani and turns to be Heteroscyphus argutus . The type specimen of Chiloscyphus quadricilius here selected is sterile, but the vegetative and male characters are convenient for a transfer into the genus Heteroscyphus , underleaves widely connate on both side with the neighbouring leaves, leaves subopposite, leaf cells with large bulging trigones, androecia at the end of short leafless lateral branches. Furthermore, the features described by Stephani together with our observation on the type perfectly match Heteroscyphus grandiflorus , even if Stephani states the leaf cells are lacking trigones. In the type specimen, the cells show large nodulous trigones.

For the distinction from Heteroscyphus caledonicus , see under this species.

The antheridium characters have not been published by Stephani in his diagnosis of Chiloscyphus grandiflorus . It can newly be described from vouchers of recently collected male shoots (e.g. Metoyer NC1688, Thouvenot NC2750).

Figures

FIG. 15. — Heteroscyphus grandiflorus (Steph.) Hürl.: A, E, H, shoot portions from different parts of a single specimen; B, D, G, underleaves; C, I, K, leaves; F, ventral margins of two adjacent leaves showing their imbrication; J, leaf and underleaf; L, cilia from leaf apex; M, cells. A, E, H, drawn from the specimen Thouvenot NC2745; B, from Thouvenot NC1486; C, D, from Thouvenot NC0752; F, from the syntype of Chiloscyphus grandiflorus Steph. (G00283070); G, from Thouvenot NC2895; I, J, from the lectotype of Chiloscyphus grandiflorus (G00069506); K, from the syntype of Chiloscyphus grandiflorus (G00283071); L, M, from Thouvenot NC2750. Scale bars: A-K, 1 mm; L, M, 20 µm.