Fig 1.
A generalized diagram of typical flowers in the Lauraceae.
Abbreviations. C, carpel; G, gland; P1, the outer whorl of tepals; P2, the inner whorl of tepals; S1, the first/outermost whorl of stamens; S2, the second whorl of stamens; S3, the third androecial whorl including either fertile stamens or staminodes; S4, the fourth androecial whorl including staminodes.
Fig 2.
Macromorphology of Syndiclis marlipoensis.
A, a floral branch; B, tip of a branch with inflorescences; C, lateral view of an inflorescence; D, apical view of a flower.
Table 1.
Locality and voucher specimens of plant materials.
Fig 3.
Development of flowers of Syndiclis marlipoensis.
A, a cyme consisting of three flower buds, the triangular SAMs develop into trimerous flowers while the elliptic SAMs develop into dimerous flowers; B, two of the three primordia of the first tepal whorl, arrow marking the position of a developing tepal (P1); C, three established primordia of the second tepal whorl (P2) showing different development rates of the primordia; D, three established primordia of the first androecial whorl (S1), arrow indicating the position of a tepal (P2) which is expected to occur, leading to a flower possessing five tepals, the two established tepal primordia showing different prominence; E, a dimerous flower bud, the established primordia of the second androecial whorl (S2); F, a dimerous flower bud, stamens of the third androecial whorl not initiated while the first and second whorl of stamens well established, arrow pointing to a minute hump in the position of the third whorl of stamens; G, a dimerous flower bud, the third whorl of stamens initiated; H, a dimerous flower bud, the fourth whorl of stamens initiated; I, a flower bud with irregular merosity, two androecial primordia (S2) initiated in the position of a stamen which is expected to occur; J, a dimerous flower bud, arrow indicating the ovular protuberance; K, a dimerous flower bud, arrow pointing to the ovule not covered by the carpel; L, a trimerous flower, the carpel flanks approximating one another, the ovule enclosed. Scale bars: B: bar = 50 μm; A, C–J: bar = 100 μm; K and L: bar = 200 μm.Abbreviations. C, carpel; G, gland; P1, the outer whorl of tepals; P2, the inner whorl of tepals; S1, the first/outermost whorl of stamens; S2, the second whorl of stamens; S3, the third androecial whorl including either fertile stamens or staminodes; S4, the fourth androecial whorl including staminodes.
Fig 4.
Variation of merosity in Syndiclis marlipoensis.
A, a dimerous flower, arrow indicating a stamen of the second androecial whorl (S2) showing three locules; B, a complex-whorled flower with trimerous plus dimerous whorls, having five tepals and five fertile stamens, arrow pointing to a missing row of floral organs, leading to the loss of a tepal (P2), a stamen (S2), and a staminode (S4); C, an irregular trimerous flower, arrow indicating a poorly developed tepal of the inner tepal whorl (P2), the adjacent stamen of the second androecial whorl (S2) in the same series missing. Scale bars: A–C: bar = 500 μm. Abbreviations. C, carpel; G, gland; P1, the outer whorl of tepals; P2, the inner whorl of tepals; S1, the first/outermost whorl of stamens; S2, the second whorl of stamens; S3, the third androecial whorl including either fertile stamens or staminodes.
Fig 5.
Development of flowers of Syndiclis aff. marlipoensis.
A, a cyme consisting of three flower buds, showing the triangular SAMs; B, three tepal primordia (P1) initiated at different rates; C, three inner tepal primordia (P2) initiated at different rates; D, three primordia of the first androecial whorl (S1) initiated; E, three primordia of the second androecial whorl (S2) initiated; F, three primordia of the third androecial whorl (S3) initiated; G, the carpel primordium initiated, arrow pointing to the staminodial primordium of the fourth androecial whorl (S4), a stamen of the third androecial whorl fused to a supernumerary stamen of the second androecial whorl; H–I, the lateral side of the carpel with concavity; J, the carpel flanks approximating one another, arrow indicating the ovular protuberance; K, fusion of the carpel flanks resulting in the enclosure of the ovule; L, a flower bearing seven tepals and seven fertile stamens, S2* and S3* representing two one-locular stamens, arrow marking the missing orthostichy leading to the loss of a tepal of the inner tepal whorl (P2), a stamen of the second androecial whorl (S2), and a staminode of the fourth androecial whorl (S4). Scale bars: A–J: bar = 100 μm; K: bar = 300 μm; L = 1 mm. Abbreviations. C, carpel; G, gland; P1, the outer whorl of tepals; P2, the inner whorl of tepals; S, a supernumerary staminal organ; S1, the first/outermost whorl of stamens; S2, the second whorl of stamens; S3, the third androecial whorl including either fertile stamens or staminodes; S4, the fourth androecial whorl including staminodes.
Fig 6.
Variation patterns of flowers in Syndiclis aff. marlipoensis.
A, an irregular tetramerous flower bud, arrow highlighting a poorly developed tepal of the inner tepal whorl (P2), the stamen of the second androecial whorl (S2) in the same orthostichy missing; B, a complex-whorled flower with trimerous plus dimerous whorls, arrow indicating a missing orthostichy including a tepal of the inner tepal whorl (P2), a stamen of the second androecial whorl (S2), and a staminode of the fourth androecial whorl (S4); C, a regular tetramerous flower bud; D, a trimerous flower, showing fusion of two adjoining stamens from the third androecial whorl (S3) and the second androecial whorl (S2). Scale bars: A and B: bar = 100 μm; C and D: bar = 200 μm.Abbreviations. G, gland; P1, the outer whorl of tepals; P2, the inner whorl of tepals; S1, the first/outermost whorl of stamens; S2, the second whorl of stamens; S3, the third androecial whorl including either fertile stamens or staminodes; S4, the fourth androecial whorl including staminodes.
Fig 7.
Cross sections of flowers of Syndiclis aff. marlipoensis showing the two lateral glands (G) attached to the base of filaments of the third androecial whorl (S3) and separate from the first androecial whorl (S1) and the first tepal whorl (P1).
Scale bars: A–C: bar = 500 μm.
Fig 8.
Structural variation of flowers in Syndiclis fooningensis (A–C) and S. anlungensis (D).
A, a dimerous flower, bar = 500 um; B, a dimerous flower with one series of floral organs aborted, bar = 500 um; C, lateral view of a dimerous flower with removal of one tepal and its inner stamen displaying enlarged glands and staminodes, bar = 500 um; D, a trimerous flower, bar = 1 mm.
Fig 9.
Structural variation of flowers in Potameia.
A, apical view of a dimerous flower of P. chartacea, bar = 500 μm; B, lateral view of a dissected flower of P. chartacea displaying the glands and two-locular anthers, bar = 200 μm; C, apical view of a flower of P. micrantha displaying the one-locular anthers, bar = 200 μm; D, a dissected dimerous flower of P. micrantha lacking stamens and glands of the 3rd whorl, bar = 200 μm; E, apical view of P. microphylla displaying the included stamens and the exposed pistil, bar = 500 μm; F, lateral view of a flower of P. microphylla displaying the minute stamens and glands of the 3rd whorl, bar = 500 μm; G, apical view of a flower of P. sp., bar = 500 μm; H, lateral view of a dissected flower of P. sp. displaying the stamens and glands of the 3rd whorl, bar = 500 μm.
Table 2.
A comparison between Syndiclis and its relatives.