Gackstroemia novae-zelandiae R.M.Schust. & J.J.Engel, 2013

Engel, John J., 2013, Austral Hepaticae 50. Gackstroemia in New Zealand, together with an interesting new species, Phytotaxa 118 (1), pp. 9-21 : 10-16

publication ID	https://doi.org/ 10.11646/phytotaxa.118.1.2
persistent identifier	https://treatment.plazi.org/id/03D387FB-FFF8-FFBC-FF2B-F8ADFC860249
treatment provided by	Felipe
scientific name	Gackstroemia novae-zelandiae R.M.Schust. & J.J.Engel
status	sp. nov.

Treatment

Gackstroemia novae-zelandiae R.M.Schust. & J.J.Engel , sp. nov. ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 )

Gackstroemiae weindorferi similis, sed caulibus (2)3-pinnatis; margine dorsali surculi primarii anguste acuteque reflexa; ramulis ultimis amphigastrio rami primi lobis maximam partem explanatis, lobis amphigastriorum ramulorum ultimorum uniformiter explanatis, cellulis folii parietibus interjacentibus inter trigonas saltem mediocriter incrassatis, lumine saepe aequaliter rotundato; amphigastriis surculi primarii distincte ad basem auriculatis, lobis in cellulam unicam vel in seriem uniseriatam e 2(-3) cellulis constantem terminatis; sporis 85–96 µm, pariete tuberculis

regularibus densis grossis instructa; elateribus 3-spiris, latioribus horum 3–4-spiris, speiris perangustis, 2 um latis; pariete capsulae 4–6-stratosa differt.

Type:— NEW ZEALAND. South Island , Westland Prov. , Cascade Road , just W of Jackson River , ca. 8–12 km SW of confluence of Jackson and Arawata Rivers, 25–90 m, Engel 22996 (holotype F!, isotype CHR!) .

Plants at maturity with principal axis ascending or the entire plant erect, copper-red at maturity but never piceous, robust, (1.2) 1.8–2.8 cm wide (widest point of opposing primary branch tips). Branching regularly (2)3-pinnate, the branches stiffly spreading (at ca. 90º or nearly so), the primary branches sometimes twisted towards base of primary axis so that the ventral faces of the branch system are oriented, in shelf-like tiers, toward the shoot base; ultimate branches with first branch underleaf typically bilobed (rarely 1- or 3-lobed), the 2 lobes subequal and mostly explanate, the lower lobe occasionally galeate. Stems rigid, the cortex of main axes in 3–4 layers of strongly thick-walled, bast-fiber like, pigmented cells; medulla of slightly firm walled, pigmented cells. Rhizoids sparsely developed, usually confined to main stem underleaves at shoot bases, the branch underleaves normally lacking associated rhizoids. Leaves of main shoot with dorsal lobes imbricate, horizontal, plane or weakly convex and with leaf tips decurved, subsymmetrically to moderately asymmetrically ± heart-shaped, the apex typically abruptly apiculate and terminating in a single cell or a hyaline uniseriate row of 2 cells, the tip cell weakly to moderately elongate and tapering to a sharp summit, the apex at times narrowly acute; dorsal margin (= margin nearest stem) narrowly and sharply reflexed, sparingly to densely ciliate in basal ca. 0.4 (the ampliate sector of margin) and with few or no cilia or teeth above or dentate-cilate throughout, the margin rarely entire, the cilia comprised of a single cell or a uniseriate row of 2–3(4) cells, the cells to 6.6:1, distinctly thick walled (esp. the terminal cell), the margin cordate to (often) auriculate at the base; ventral margin with armature similar but broader based and laciniiform. Ventral lobe deeply and asymmetrically divided into a typically explanate lobule and a much larger (esp. wider) stylus. Lobule (on leaves of main shoot) explanate, not or rarely transformed into a water sac, often sulcate. Stylus flat, lamelliform, with margins plane or weakly reflexed, the stylus broad ovate-elliptic to orbicular to oblate, entire or sparingly to copiously ciliate, particularly above. Leaves of 2º and 3º branches smaller, simpler, lacking a third lobe (stylus), with dorsal lobe margins of 2º branches fringed with regularly spaced cilia, the cilia comprised of 2–4 elongated (the tip cell notably so), thick-walled cells, the cilia of 3º branch leaves appearing like eyelashes. Leaves of ultimate branches with lobules saccate, clavate, with a stiff cilium at the summit apex of the slit-like incision of the sac. Cells occurring in ± regular tiers and vertical rows, with trigones bulging, often ± confluent, the intervening walls between trigones at least moderately thickened and often notably so, the lumina usually evenly rounded, the median cells 18–22 µm wide, 19–28 µm long; surface smooth. Oil-bodies ( Schuster, 1973) glistening, homogeneous, usually 8–15 per cell, ellipsoidal to bacilliform, very small. Underleaves of stems and primary branches large, ± distinctly imbricate, subreniform to oblate, shallowly bilobed; lobes never transformed into water sacs, typically reflexed and canaliculatecucullate, terminating in a single cell or a uniseriate row of 2(3) cells that are isodiametric or at most 2X longer than wide; lamina with margins narrowly and sharply in part or throughout reflexed (and appearing grooved) and with the reflexed portion confluent with the recurvature of the lobes, the lamina margins dentate-cilate in basal 0.35–0.5, occasionally armed throughout, sporadically entire, distinctly auriculate at base; underleaves of ultimate branches with lobes uniformly explanate (suboptimal populations sporadically with lobes transformed into water sacs, especially in distal sector of branch).

Plants dioecious. Androecia numerous, confined to apices of secondary and tertiary (ultimate) branchlets, rather short and compactly spicate, mostly decurved to somewhat coiled; bracts in 2–4(5) pairs, imbricate, bilobed to less than 0.4, the dorsal lobe somewhat larger, broadly acute, rarely with a short awn, the dorsal margin of the dorsal lobe and lamina entire, the lamina margin sharply reflexed toward the base, the ventral lobe acute, with margins plane, occasionally reflexed and then the lobe sulcate, the summit rarely with a short awn, the lobe margins entire; antheridia 1 per bract, the subspherical body occupying almost the entire ventricose bract base, the stalk coiled, very long, of 18–20 cells; bracteoles present throughout, shallowly bilobed, strongly spreading to squarrose, the lobes often reflexed, acute but never ending in cilia. Gynoecia with the coelocaule erect, fleshy, slenderly ellipsoidal, with sterile archegonia inserted at the apex of the caplike shoot-calyptra, devoid of paraphyses or paraphyllia, and hidden even at maturity by the 10–12 series (gyres) of sheathing, mutually closely shingled bracts and bracteoles, forming a compact, budlike structure; bracts membraneous, narrowly ovate, bifid to ca. 0.25 by the narrowly acute lobes, the lobes and distal sector of lamina densely and copiously armed with long, tortuous cilia, the basal sector of lamina distantly and sparsely armed to subentire; bracts of innermost series inserted near perianth base (if latter is developed) and closely entheathing it, distinctly smaller and shorter, quite hidden within the penultimate 2–3 series of large bracts and bracteoles; uppermost bracts sometimes ± connate to form a perianth-like sheath, which, if present, is membraneous and fragile, the innermost bracts sometimes free dorsally or completely free and then a perianth-like structure lacking; perianth-like structure, if developed, not exserted beyond bracts, ± cylindrical, narrowing toward the ± contracted mouth, with several broad plicae, the mouth and free margins densely fringed with tortuous cilia like those of bracts below, the cilia mostly uniseriate to base, at times with up to 3 branches, with to 14 cells in the uniseriate row, the cells thick walled, and capillary throughout and with swollen septa.

Capsule elongate-cylindrical (ca. 1–1.2 mm wide × 3.5 mm long), the valves normally permanently coherent at the beaked apex, the lateral slits extending to base of capsule, the capsule wall 86–110 µm thick, 4–6-stratose, the outer layer of cells very high, 2-3X higher than wide, the outer layer of cells equal to thickness of 2–2.8 of interior strata, the cells within with thin and delicate walls, the cells collapsing with age, the inner face of the valve with local patches of cells that are often sloughed off; outer layer of cells short oblong-rectangular, with all longitudinal walls with thick, even, often ± lens-like, hyaline to yellowish sheets of wall material, without nodular thickenings, the transverse walls thin or with moderate even thickenings; intermediate layers with hyaline, semiannular or annular thickenings, or with thickenings merely at the cell angles; innermost layer of cells irregularly rectangular, with very weak, often indistinct and/or ill-defined, very weakly pigmented semiannular bands, the bands often incomplete.

Spores exceptionally large, 85–96 µm in diam., with numerous, ± regular, dense, coarse, high, juxtaposed tuberculae, the tuberculae rounded at the summit and in profile appearing feebly stalked; spore: elater diam. ratio ca. 9:1. Elaters tortuous and flexuous, variable: 7–15 µm wide, the narrower ones closely 3-spiral (2- spiral on ends), the wider ones 3–4-spiral, the spirals very narrow (2 µm wide).

Distribution:— New Zealand: South Island (20–610 m), North Island (720–1320 m).

Comments:—Plants of G. novae-zelandiae and G. weindorferi are both relatively vigorous, but may be readily distinguished by a number of distinctive characters from both gametophyte and sporophyte. Gackstroemia novae-zelandiae is a larger plant, usually 1.8–2.5 cm wide at the widest point between opposing primary branch tips, and is nearly always 3-pinnate, vs. medium in size (to 9–17 mm wide at the widest point between opposing primary branch tips) and mostly 2(3)-pinnate, with tertiary branches irregularly present and distributed, i.e., they are on some secondary branches while others totally lack them in G. weindorferi . The underleaf lobes of ultimate branches in G. novae-zelandiae are uniformly explanate ( Fig. 1 View FIGURE 1 : 11), and the first branch underleaf lobes of such branches are mostly explanate ( Fig. 1 View FIGURE 1 : 11), (the lower lobe is only occasionally saccate) vs. ultimate branches with underleaf lobes uniformly saccate and the first branch underleaf lobes are likewise typically uniformly saccate (the upper lobe in some populations is at times explanate) in G. weindorferi ( Fig. 3 View FIGURE 3 : 8). In G. novae-zelandiae the dorsal margin of leaves on main shoots is narrowly and sharply reflexed ( Fig. 1 View FIGURE 1 : 2) vs. plane and not reflexed in G. weindorferi ( Fig. 3 View FIGURE 3 : 1). The stylus of main shoot leaves in G. novae-zelandiae is flat, with margins plane or at most only weakly reflexed ( Fig. 1 View FIGURE 1 : 1) vs. the stylus of main shoot leaves cucullate, with strongly reflexed margins in G. weindorferi ( Fig. 3 View FIGURE 3 : 2). Underleaf characters are also useful. In G. novae-zelandiae the underleaves on the main shoot are distinctly auriculate at the base ( Fig. 1 View FIGURE 1 : 7, 8) while in G. weindorferi the underleaves of main shoot are narrowed and angled to base, and the tissue adjacent to the apex and base of the U-shaped insertion line forms an inverted triangle ( Fig. 3 View FIGURE 3 : 5, 6). In G. novae-zelandiae main shoot underleaves terminate in a single cell or a uniseriate row of 2(3) isodiametric or moderately elongate cells (at most 2:1) ( Fig. 1 View FIGURE 1 : 9, 10) vs. the lobe terminating in a uniseriate row of (2)3-5 elongated cells in G. weindorferi ( Fig. 3 View FIGURE 3 : 7). It should be noted, though, that small phases of G. alpina may have lobes that terminate in a single cell or a uniseriate row of two weakly elongated cells. The leaf cells of G. novae-zelandiae have a noteworthy areolation: the intervening walls between trigones are at least moderately thickened, and often are strongly so lending an evenly and smoothly rounded contour to the lumina ( Fig. 1 View FIGURE 1 : 5). In G. weindorferi , on the other hand, the intervening walls between trigones are thin, defining an irregular lumina boundary, which alternately curves inward and outward, i.e., irregularly sinuate ( Fig. 3 View FIGURE 3 : 4). When this character is optimally expressed, each lumen boundary has several outward and inward protrusions defined by the alternation of bulging trigones and thin-walled intervening sectors, but when suboptimally expressed only one or two protrusions are present.

Androecial bracts also will differentiate G. novae-zelandiae and G. weindorferi . The ♂ bracts of G. weindorferi have lobes with an awn at the apex and several inconspicuous, unicellular, sharp teeth on the dorsal margin of the dorsal lobe and lamina. The bract lobes of G. novae-zelandiae taper to the apex and typically are devoid of an awn at the summit and the dorsal margin of the dorsal lobe and lamina is entire.

Several sporophyte characters differentiate G. novae-zelandiae and G. weindorferi . The spores in G. novae-zelandiae are 85–96 µm in diameter, with the wall covered by numerous, closely spaced, rather high tubercles ( Fig. 2 View FIGURE 2 : 9), whereas those in G. weindorferi are very different: 47–58 µm in diameter and the wall is distally reticulate, with an irregularly anastomosing network of low, fine ridges and ill-defined areolae ( Fig. 3 View FIGURE 3 : 11); the proximal field is 30–37 µm wide and distantly and irregularly finely papillose-vermiculate. Elaters in G. novae-zelandiae are 3-spiral but may be 2-spiral toward the tips, or wider and 3–4-spiral, and the spirals are quite narrow, being only 2 µm wide ( Fig. 2 View FIGURE 2 : 10). The elaters of G. weindorferi are variable and may be 1-spiral throughout, or 2-spiral but 1-spiral at the tips ( Fig. 3 View FIGURE 3 : 12), or 2-spiral throughout; spirals are wider than those of G. novae-zelandiae , at times being over twice as wide. In G. novae-zelandiae the capsule is 4–6-layered vs. 3(4) or 3-4(locally 5) layered in G. weindorferi .

The gynoecia of G. novae-zelandiae and G. weindorferi are very distinctive; nothing like it occurs in other taxa of the family. Unlike in Lepidolaena species , in which there is an externally evident coelocaule, that of G. novae-zelandiae and G. weindorferi is quite hidden by the many series of tightly imbricate, concave, erect, mutually involute and sheathing bracts and bracteoles. The gynoecial apparatus in both species lends an aspect much like the bud of a dicotoledonous tree with tightly imbricate bud scales. As noted in Schuster (1973, p. 348), the ciliate margins of the bracts "serve to reinforce the illusion." In G. novae-zelandiae the largest bracts and bracteoles are in the third to fourth or third to sixth gyres (those of gyres 1–2 or 1–3 are somewhat smaller), then decrease strongly and progressively in size (gyres 6-8); cf. Schuster (1984, fig. 75: 1–8); bracts and bracteoles occur in 10-12 gyres in this species. In G. weindorferi the bracts and bracteoles occur in 4–5 gyres that increase in size toward the perianth. In G. novae-zelandiae a perianth-like sheath is present or absent, depending on the degree of fusion of innermost bracts and bracteole, which is variable. Complete fusion may occur in the species, but incomplete fusion also may occur. The bracts are sometimes free ventrally ( Fig. 2 View FIGURE 2 : 3), while dorsally complete fusion between bracts and bracteole may occur ( Fig. 2 View FIGURE 2 : 2). In other cases fusion is low and only ca. 0.35 the perianth length. Sometimes there is no trace of fusion among the inner, reduced bracts ( Schuster, 1984, fig. 75: 10). Schuster (1984, fig. 75) illustrated the gynoecium of a plant that he referred to as " G. weindorferi ," but it is also the material diagnosed in detail in Schuster (1973); that plant is identical to the species newly described here. In cases of complete or partial fusion, the "perianth" has a similar basic form to that of G. weindorferi (see Grolle, 1967, pl. 6d, f). The perianth in G. weindorferi typically is present, with complete fusion of components to form a complete ring as illustrated in Fig. 3 View FIGURE 3 : 10 and by Grolle (1967, pl. 6d), although note that a rather deep sinus occurs. At times the ring is interrupted (on the ventral side of the perianth) by 2 of the margins being totally free from one another to the base, but in such cases the 2 free margins broadly overlap and one side is inserted slightly lower.

Gackstroemia novae-zelandiae is a vigorous plant, and, when well developed, branching has the aspect of the moss Hylocomium , with an ascending, rigid main axis which divides copiously and repeatedly into a "frond," formed of numerous branches, and lying in a single plane. The branching typically is regularly 3- pinnate, with primary branches spreading at stiff ± right angles. The entire plant may be more or less in one plane, but a curious condition of the branches often occurs, particularly in well-developed populations, where primary branches are twisted towards the base of the primary axis. In such plants the ventral face of the branch system, consisting of primary, secondary, and tertiary branches, is oriented toward the shoot base and together form shelf-like tiers. Secondary branches (and androecia) in such phases are semipendulous and droop or descend toward the base of the main shoot. This condition often is present throughout a population.

This species has been in manuscript form for nearly 20 years and was originally intended to appear in a joint publication by Dr. R. M. Schuster and me. For various reasons this manuscript did not further develop, and I am presenting the species for publication at this time.