Seed Geometry in the Vitaceae: Comparison
Please note this is a comparison between Version 2 by Camila Xu and Version 1 by Emilio Cervantes.

The Vitaceae Juss., in the basal lineages of Rosids, contains sixteen genera and 950 species, mainly of tropical lianas. The family has been divided in five tribes: Ampelopsideae, Cisseae, Cayratieae, Parthenocisseae and Viteae. Seed shape is variable in this family and is described based on the comparison of bi-dimensional seed images with geometric models. 

Ten morphological types are described in the Vitaceae. Seven of them are general and three specific. Among the general types, three are shared with the Arecaceae and correspond to geometric figures well described (lenses, superellipses and elongated waterdrops). Four additional groups include waterdrops, normal or rounded, heart curves, normal or rounded, elongated heart curves and other elongated curves, respectively. Finally, the three specific types correspond to heart curves of the Cayratia and Pseudocayratia types, heart curves of the Squared Heart Curve (SqHC) type of Ampelocissus and Ampelopsis, and Elongated Superellipse-Heart Curves (ESHCs), frequent in Tetrastigma species and observed also in Cissus species and R. rhomboidea. All these groups are defined by geometric models obtained by the representation of algebraic equations. Modifications in the equations result in models adjusting to the shape of seeds for each species.

  • endosperm
  • geometry
  • morphology
  • seed shape
  • Vitaceae

1. Introduction

The Vitaceae Juss. contains sixteen genera with ca. 950 species of lianas primarily distributed in the tropics with some genera in the temperate regions. The [1][2]Leeaceae Dumort., with a single genus of 34 species, mostly shrubs and small trees rather than lianas, included in the family in the APG IV [1], was later recognized as a separate family [2,3]. Both families constitute the order Vitales, one of the basal lineages of Rosids, whose closest relative remains controversial [4,5].
The Vitaceae has been divided in five tribes[3]  [3] (Table 1): (I) Ampelopsideae J. Wen and Z. L. Nie (Ampelopsis Michx., Nekemias Raf., Rhoicissus Planch., Clematicissus Planch.); (II) Cisseae Rchb. (Cissus L.); (III) Cayratieae J.Wen and L.M.Lu (Cayratia Juss. Ex Guill, Causonis Raf., Acareosperma Gagnep., Afrocayratia, Cyphostemma (Planch.) Alston, Pseudocayratia J.Wen, L.M.Lu and Z.D.Chen, Tetrastigma Planch.); (IV) Parthenocisseae J.Wen and Z.D.Chen (Parthenocissus Planch.) and (V) Viteae Dumort (Ampelocissus Planch., and Vitis L.).  Cayratia and Cyphostemma were included in Cissus by Linné and Planchon considered the former as a section of Cissus [6,7].
Table 1. A summary of the taxonomy of the Vitaceae. The approximate number of species in each tribe and genus is given between parentheses. Data adapted from [3].
L. (75)

 

 
TribeGenera

Species (References for the Images)

Species (References for the Images)
I. Ampelopsideae (47)

I. Ampelopsideae

(15/47)

Ampelopsis Michx. (18)Nekemias Raf. (9)

Ampelopsis Michx.

(13/18)

Ampelopsis aconitifolia [36], A. arborea [37], A. bodinieri

contains a summary of groups based on morphological seed types for the analysed species .

Table 3. A summary of groups based on morphological seed types for the analysed species in the Vitaceae. The number of cases found in each group is given between dashes.

Group (Geometric Model)

Examples

Group I (Lenses)-3-

Cissus quadrangularis [44], C. sterculiifolia [31], Tetrastigma petraeum [51][36], A. cantoniensis [31,36], A. cordata [38], A. chaffanjoni [36], A. delavayana [31], A. denudata [30], A. glandulosa [39], A. grossedentata [31], A. humulifolia [36], A. japonica [36], A. megalophylla [31,36]

 
Rhoicissus Planch. (14)

 

Group II (Superellipses)-7-

Rhoicissus Planch.

(2/14)

Ampelocissus bravoi [42], C. reniformis [31,41], Cyphostemma elephantopus [49], C. laza [31], Tetrastigma campylocarpum [51], T. caudatum [51], T. henryi [51]

Rhoicissus

revoilii [31], R. rhomboidea [31]

 

II. Cisseae

Clematicissus Planch. (6)

(33/300)

Cissus L.

Group III (Elongated water drops)-15-

Ampelopsis arborea [37],(33/300)

Cayratia imerinensis

[47], Cissus aralioides [35,40], C. cornifolia [40], C. erosa [43], C. integrifolia [40,42], C. petiolata [40], C. pileata [40], C. populnea [40], C. verticillata [31,41,42,45], C. sciaphila [40], C. smithiana [40], C. willardii [42], Cyphostemma junceum [31], V. vulpina [61,62]

Cissus antarctica

[31], C. aralioides [35,40], C. barbeyana [40], C. bosseri [40], C. cactiformis [40], C. campestris [31,41,42], C. cornifolia [40], C. descoingsii, [31,41], C. diffusiflora [40], C. elongata [40], C. erosa [43], C. floribunda [40], C. fuliginea [31], C. granulosa [31], C. hastata [40], C. hypoglauca [31], C. integrifolia [40,42], C. leucophlea [40], C. penninervis [31], C. petiolata [40], C. pileata [40], C. populnea [40], C. quadrangularis [44], C. reniformis [31,41], C. repens [40], C. sciaphila [40], C. smithiana [40], C. sterculiifolia [31], C. subtetragona [40], C. trianae [31], C. tuberosa [42], C. verticillata [31,41,42,45], C. willardii [42],

II. Cisseae (300)Cissus L. (300)

III. Cayratieae

(40/365)

Group IV (Water drops, normal or rounded)-14-

Causonis Raf. (1/9)

Ampelopsis bodinieri [36], A. glandulosa [36,39], A. humulifolia [36], Cayratia cheniana [46], Cissus campestris [31,41,42], C. fuliginea [31], C. tuberosa [42], C. granulosa [31], Parthenocissus dalzielii [36], Tetrastigma triphyllum [31,51], Vitis amurensis [45,56], V. labrusca [45,54,62]

Causonis sp.

[46]

, V. palmata

[59],

III. Cayratieae (368)Cayratia Juss. (25)

V. rupestris

[45]

 

Cayratia Juss.

(7/60)

Group V (Heart curves normal or rounded)-19-

Ampelopsis aconitifolia [36], A. chaffanjoni [36], A. cordata [38], A. japonica [36], Parthenocissus heptaphylla [31], P. heterophylla [36], P. henryana [36], P. himalayana [51,53], P. quinquefolia [54], P. vitacea [31], P. tricuspidata [36,37,45], Rhoicissus revoilii [31], T. lanceolarium [30], Vitis cinerea [57], V. flexuosa [54], V. lanatoides [58], V. latisulcata

Cayratia cheniana

[46], C. geniculata [31], C. imerinensis [47], C. japonica [31,48], C. oligocarpa [31], C. saponaria [31], C. sp. [African, 46]

 Causonis Raf. (30)

 

Cyphostemma

(Planch.) Alston

(3/200)

Cyphostemma elephantopus [49], C. laza [31], C. junceum [31]

 Acareosperma Gagnep. (1)

 

Pseudocayratia J. Wen, L.M.Lu and Z.D.Chen

(3/5)

Pseudocayratia dichromocarpa [50], P. pengiana [50], P. speciosa [50,52]

 Afrocayratia (7)

 

Tetrastigma

(Miq.) Planch.

(26/100)

Tetrastigma campylocarpum [51], T. cauliflorum [51], T. caudatum [51], T. delavayi [51], T. dichotomum [52], T. formosanum [51], T. harmandi [31], T. hemsleyanum [31,51], T. henryi [51], T. hypoglaucum [51], T. jinghongense [51], T. kwangsiense [30,31], T. lanceolarium [30], T. laoticum [51], T. obovatum [51,52], T. obtectum [51,52], T. pachyllylum [51], T. pedunculare [31,51,52], T. petraeum [51], T. retinervum [51], T. rumicispermum [31,51,52], T. serrulatum [51], T. sichouense [51], T. thorsborneorum [51], T. triphyllum [31,51], T. xishuangbannaense [31,51]

 

IV. Parthenocisseae

(11/16)

Cyphostemma (Planch.) Alston (200)

Parthenocissus Planch.

(9/14)

Parthenocissus dalzielii [36], P. heptaphylla [31], P. henryana [36], P. heterophylla [36], P. himalayana [53], P. laetevirens [36], P. quinquefolia [54], P. tricuspidata [36,37,45], P. vitacea [31]

 Pseudocayratia J. Wen,L.M.Lu and Z.D. Chen (5)

 

Yua C.L.Li (2/2)

Yua austro-orientalis [31], Y. chinensis [31]

 

V. Viteae

Tetrastigma (Miq.) Planch. (100)

(32/190)

Ampelocissus Planch.

(13/115)

Ampelocissus acapulcensis [30], A. bombycina [30], A. bravoi [42], A. cavicaulis [30], A. erdvendbergiana [30], A. grantii [30], A. javalensis [30,42], A. latifolia [30], A. macrocirrha [30], A. martinii [42], A. obtusata [30], A. ochracea [30], A. robinsonii [30]

IV. Parthenocisseae (16)Parthenocissus Planch. (14)

 

Vitis L.

(19/75)

Vitis aestivalis [55],

 Yua C.L.Li (2)
V. Viteae (190)Ampelocissus Planch. (115)
 Vitis L. (75)
TribeGenera
I. Ampelopsideae (47)Ampelopsis Michx. (18)Nekemias Raf. (9)
 Rhoicissus Planch. (14)
 Clematicissus Planch. (6)
II. Cisseae (300)Cissus L. (300)
III. Cayratieae (368)Cayratia Juss. (25)
 Causonis Raf. (30)
 Acareosperma Gagnep. (1)
 Afrocayratia (7)
 Cyphostemma (Planch.) Alston (200)
 Pseudocayratia J. Wen,L.M.Lu and Z.D. Chen (5)
 Tetrastigma (Miq.) Planch. (100)
IV. Parthenocisseae (16)Parthenocissus Planch. (14)
 Yua C.L.Li (2)
V. Viteae (190)Ampelocissus Planch. (115)
 Vitis
Cissus is the largest genus in the family with 300 species of complex classification[4].

is the largest genus in the family with 300 species of complex classification [8].

Cyphostemma is second, with 200 species of an interesting diversity in their range of distribution as well as in growth habits (vines and lianas, herbs, stem succulents and a tree)[5].

is second, with 200 species of an interesting diversity in their range of distribution as well as in growth habits (vines and lianas, herbs, stem succulents and a tree) [9].

Vitis

has seventy-five inter-fertile wild species distributed in three continents under subtropical, Mediterranean and continental-temperate climatic conditions.

Vitis vinifera

L. is the species with highest economic importance in the family with some taxonomic uncertainty about the differentiation between

V. vinifera

L. subsp.

vinifera

and

V. vinifera

L. subsp.

sylvestris (Willd.) Hegi[6][7]. Thousands of cultivars of

(Willd.) Hegi [10,11]. Thousands of cultivars of

V. vinifera

are used worldwide in Viticulture. Species of other genera are widely cultivated, such as

Parthenocissus quinquefolia

(L.) Planch., the Virginia creeper, in temperate areas, and

Cissus incisa Des Moul., the grape ivy, in tropical areas. 
The taxonomy and phylogenetic relationships of the Vitaceae are far from complete and will benefit from an accurate description of seeds in the unambiguous terms of geometry. From a practical point of view, the classification based on geometric models may contribute to the distinction between wild and crop grapes of Vi

Des Moul., the grape ivy, in tropical areas. Species of the genus Tetrastigma are the only host plants for the parasitic plant Rafflesia vinarnoldiifera[7]

.

R.Br., Rafflesiaceae, which is native only to a few areas within the Malay Archipelago [12].

2. Seed Morphology in the Vitaceae

2.1. Quantification of Seed Shape by Geometric Models

The silhouettes of bi-dimensional images of seeds often resemble geometric figures that can be used as models for the description and quantification of seed shape in plant families. A recent review of the geometry of seeds in the Arecaceae described a series of models useful for the analysis of seed shape in this family [13]. Geometric models included the ellipses (the circle is a particular type of ellipse), ovals, lemniscates, superellipses, cardioid and derivatives, lenses and the water drop curve[8] [13]. The reader is referred to this review for the algebraic description of the models and their application in the morphometry of seeds in the Arecaceae. The application of geometric models in morphometry is based on the comparison of bi-dimensional images of well oriented seeds with these figures by means of image programs working in two layers (Adobe Photoshop, Corel Photo Paint…). The two images (seed and model) can be superimposed searching for a maximum similarity and the ratio between shared and total surface areas, that we have termed J index, is calculated with the data obtained in ImageJ[9] [15]. J index measures the percent of similarity between two images (the seed and the model) and provides information on overall seed shape[10] [11][16,17]. Bidimensional seed images of many plant species adjust well to one of three morphological types: the ellipse, the oval and the cardioid[12] [18]. The seeds of the model plant Arabidopsis thaliana (L.) Heynh., those of the model legumes Lotus japonicus (Regel) K.Larsen and Medicago truncatula Gaertn., as well as the seeds of Capparis spinosa L., in the Capparaceae ,and Rhus tripartita DC. in the Anacardiaceae, and species of Silene addjust well to cardioids or modified cardioids [13][14][15][16][17][18][19,20,21,22,23]. The seeds of Ricinus communis L. and Jatropha curcas L. in the Euphorbiaceae and those of cultivars of Triticum sp. in the Poaceae adjust well to ellipses of varied x/y ratio[19][20][21] [24,25,26]. Oval shaped seeds occur frequently in the Cucurbitaceae, Berberidaceae, Eupteleaceae and Lardizabalaceae[22][23] [27,28], while the cardioid is more common in Papaveraceae[23] [28]. A given geometric type is sometimes associated with other morphological or ecological characteristics. For example, cardioid-type seeds awere observed to be more frequently in small-sized seeds, while elliptic shape is more frequent in larger seeds[12] [18]. In the Malvaceae, cardioid type seeds are associated with small herbs of annual cycle[24] [29].

2.2. Seed Morphology in the Vitaceae

The seeds of the Vitaceae share structural characteristics. The endosperm presents in transversal section a typical “M” shape coincident with a pair of ventral in-folds and a dorsal chalaza knot allowing the identification of fossil seeds in this family[25].
Seed shape in the Vitaceae is variable and seeds resembling geometric figures are frequent in this family. The seeds of Ampelocissus are pyriform, oval, or round in dorsal or ventral view[26] [30]. The seeds of Cissus species are often described as globose with a pointed base, elliptic in outline or oblong (see, for example, [33,34,35]). These adjectives and other like sub-globose or terete are also applied to seed descriptions in other genera suggesting two important points: (1) The seeds of the Vitaceae are suitable for the comparison with geometric figures used as models. (2) The comparison may be quantitative, yielding measures that contribute to taxonomy. Table 2 contains a list of 131 species in the Vitaceae whose seeds have been observed for this work.
Table 2.
A summary of the 131 species for which seed shape has been analysed in this work.

Tribe

(Species Observed/Total)

Tribe

(Species Observed/Total)

Genera

(Species Observed/Total)

Genera

(Species Observed/Total)

[58],

V. tsoi

[31,41],

V. wilsoniae

[31,41]

Group VI (Elongated Heart curves)-6-

Ampelocissus acapulcensis [30], Cissus oligocarpa [31]. V. eolabrusca [54], V. grayensis [58], V. pseudorotundifolia [54], V. tiliifolia [60]

Group VII (Other elongated types)-11-

Ampelopsis megalophylla [31,36], Causonis sp. [46], Cayratia saponaria [31], Cissus trianae [31], C. hypoglauca [31], Parthenocissus laetevirens [36], T. hypoglaucum [51] Vitis aestivalis [55], V. rotundifolia [31,41,54], Yua austro-orientalis [31], Y. chinensis [31]

Group VIII (Heart curves of the Cayratia and Pseudocayratia types)-7-

Cayratia japonica [31,48], Cayratia sp. [African, 46], Pseudocayratia dichromocarpa [50], P. pengiana [50], P. speciosa [50,52], Tetrastigma formosanum [51], T. pedunculare [31,51,52]

Group IX (Heart curves of the SqHC type of Ampelocissus and Ampelopsis)-15-

Ampelocissus bombycina [30], A. cavicaulis [30], A. erdvendbergiana [30], A. grantii [30], A. javalensis [30,42], A. latifolia [30], A. macrocirrha [30], A. martinii [42], A. obtusata [30], A. ochracea [30], A. robinsonii [30], Ampelopsis cantoniensis [31,36], A. delavayana [31], A. denudata [30], A. grossedentata [31]

Group X Elongated Superellipse-heart curves-16-

Cissus elongata [40], C. penninervis [31], Rhoicissus rhomboidea [31], Tetrastigma hemsleyanum [31,51], T. jinghongense [51], T. laoticum [51], T. cauliflorum [51], T. dichotomum [52], T. harmandi [31], T. pachyllylum [51], T. kwangsiense [30,31], T. obovatum [51,52], T. obtectum [51,52], T. retinervum [52], T. serrulatum [51], T. sichouense [51]

Undefined-18-

Cayratia geniculata [31], Cissus antarctica [31], C. barbeyana [40], C. bosseri [40], C. cactiformis [40], C. descoingsii, [31,41], C. diffusiflora [40], C. floribunda [40], C. hastata [40], C. leucophlea [40], C. repens [40], C. subtetragona [40], T. delavayi [51], T. rumicispermum [31,51,52], T. thorsborneorum [51], T. xishuangbannaense [31,51], V. brandoniana [54], V. rostrata [54]

V. amurensis

Group (Geometric Model)Examples

[45,56],

V. brandoniana

[54],

V. cinerea

[57],

V. eolabrusca

[54],

V. flexuosa

[54],

V. grayensis [

58],

V. labrusca

[45,54,62],

V. lanatoides [

58], V. latisulcata [58], V. palmata [59], V. pseudorotundifolia [54], V. rostrata [54], V. rotundifolia [31,41,54], V. rupestris [45], V. tiliifolia [60], V. tsoi [31,41], V. vulpina [61,62], V. wilsoniae [31,41]

I. Ampelopsideae

(15/47)
Ampelopsis Michx.

Group I (Lenses)-3-(13/18)Cissus quadrangularis [44], C. sterculiifolia [31], Tetrastigma petraeum [52]Ampelopsis aconitifolia [36], A. arborea [37], A. bodinieri [36], A. cantoniensis [31,36], A. cordata [38], A. chaffanjoni [36], A. delavayana [31], A. denudata [30], A. glandulosa [39], A. grossedentata [31], A. humulifolia [36], A. japonica [36], A. megalophylla [31,36]
 Rhoicissus Planch.

(2/14)
Group II (Superellipses)-7-Ampelocissus bravoi [42], C. reniformis [31,41], Cyphostemma elephantopus [49], C. laza [31], Tetrastigma campylocarpum [52], T. caudatum [52], T. henryi [52Rhoicissus revoilii [31], R. rhomboidea [31]
]II. Cisseae

(33/300)
Group III (Elongated water drops)-15-Cissus L.

(33/300)
Ampelopsis arborea [37], Cayratia imerinensis [47], Cissus aralioides [35,40], C. cornifolia [40], C. erosa [43], C. integrifolia [40,42], C. petiolata [40], C. pileata [40], C. populnea [40], C. verticillata [Cissus antarctica [31], C. aralioides [35,40], C. barbeyana [40], C. bosseri [40], C. cactiformis [40], C. floribunda [40], C. fuliginea [31], C. granulosa [31], C. hastata [40], C. hypoglauca [31], C. integrifolia [40,42], C. leucophlea [40], C. penninervis [31], C. petiolata [40], C. pileata [40], C. populnea [40], C. quadrangularis [44], C. reniformis [31,41], C. repens [40], C. sciaphila [40], C. smithiana [40], C. sterculiifolia [31], C. subtetragona [40], C. trianae [31], C. tuberosa [42], C. verticillata [31,41,42,45], C. willardii [42],
31,41,42,45], C. sciaphila [40], C. smithiana [40], C. willardii [42], Cyphostemma junceum [31], V. vulpina [59,62]], C. campestris [31,41,42], C. cornifolia [40], C. descoingsii, [31,41], C. diffusiflora [40], C. elongata [40], C. erosa [43III. Cayratieae

(40/365)
Causonis
Group IV (Water drops, normal or rounded)-14- Raf. (1/9)Ampelopsis bodinieri [36], A. glandulosa [36,39], A. humulifolia [36], Cayratia cheniana [46], Cissus campestris [31,41,42], C. fuliginea [31], C. tuberosa [42], C. granulosa [31], Parthenocissus dalzielii [36], Tetrastigma triphyllum [31,52], Vitis amurensis [45,56], V. labrusca [45,54,59], V. palmata [60], V. rupestris [45]Causonis sp. [46]
 Cayratia Juss.

(7/60)
Group V (Heart curves normal or rounded)-19-Ampelopsis aconitifolia [36], A. chaffanjoni [36], A. cordata [38], A. japonica [36], Parthenocissus heptaphylla [31], P. heterophylla [36], P. henryana [36], P. himalayana [52,53], P. quinquefolia [54], P. vitacea [31], P. tricuspidata [36,37,45], Rhoicissus revoilii [31], T. lanceolarium [30], Vitis cinerea [57], V. flexuosa [54], V. lanatoides [58], V. latisulcata [58], V. tsoi [31,41], V. wilsoniae [31,41]Cayratia cheniana [46], C. geniculata [31], C. imerinensis [47], C. japonica [31,48], C. oligocarpa [31], C. saponaria [31], C. sp. [African, [46]]
 Cyphostemma

Group VI (Elongated Heart curves)-6-(Planch.) Alston

(3/200)
Ampelocissus acapulcensis [30], Cissus oligocarpa [31]. V. eolabrusca [54], V. grayensis [58], V. pseudorotundifolia [54], V. tiliifolia [61]Cyphostemma elephantopus [49], C. laza [31], C. junceum [31]
 Pseudocayratia J. Wen, L.M.Lu and Z.D.Chen

(3/5)
Pseudocayratia dichromocarpa [50], P. pengiana [50], P. speciosa [50,51]
 Tetrastigma

(Miq.) Planch.

(26/100)
Tetrastigma campylocarpum [52], T. cauliflorum [52], T. caudatum [52], T. delavayi [52], T. dichotomum [51], T. formosanum [52], T. harmandi [31], T. hemsleyanum [31,52], T. henryi [52], T. hypoglaucum [52], T. jinghongense [52], T. kwangsiense [30,31], T. lanceolarium [30], T. laoticum [52], T. obovatum [51
Group VII (Other elongated types)-11-Ampelopsis megalophylla [31,36], Causonis sp. [46], Cayratia saponaria [31], Cissus trianae [31], C. hypoglauca [31], Parthenocissus laetevirens [36], T. hypoglaucum [52] Vitis aestivalis [55], V. rotundifolia [31,41,54], Yua austro-orientalis [31], Y. chinensis [31]
Group VIII (Heart curves of the Cayratia and Pseudocayratia types)-7-Cayratia japonica [31,48], Cayratia sp. [African, [46]], Pseudocayratia dichromocarpa [50], P. pengiana [50], P. speciosa [50,52], Tetrastigma formosanum [51], T. pedunculare [31,51,52],52], T. obtectum [51,52], T. pachyllylum [52], T. pedunculare [31,51,52], T. petraeum [52], T. retinervum [52], T. rumicispermum [31,51,52], T. serrulatum [52], T. sichouense [52], T. thorsborneorum [52], T. triphyllum [31,52], T. xishuangbannaense [31,52]
IV. Parthenocisseae

(11/16)
Group IX (Heart curves of the SqHC type of Ampelocissus and Ampelopsis)-15-Parthenocissus Planch.

(9/14)
Ampelocissus bombycina [30], A. cavicaulis [30], A. erdvendbergiana [30], A. grantii [30], A. javalensis [30,42], A. latifolia [30], A. macrocirrha [30], A. martinii [42], A. obtusata [30], A. ochracea [30], A. robinsonii [30], Ampelopsis cantoniensis [31,36], A. delavayana [31], A. denudata [30], A. grossedentata [31]Parthenocissus dalzielii [36], P. heptaphylla [31], P. henryana [36], P. heterophylla [36], P. himalayana [53], P. laetevirens [36], P. quinquefolia [54], P. tricuspidata [36,37,45], P. vitacea [31]
 Yua C.L.Li (2/2)
Group X Elongated Superellipse-heart curves-16-Cissus elongata [40], C. penninervis [31], Rhoicissus rhomboidea [31], Tetrastigma hemsleyanum [31,52], T. jinghongense [52], T. laoticum [52], T. cauliflorum [52], T. dichotomum [51], T. harmandi [31], T. pachyllylum [52], T. kwangsiense [30,31], T. obovatum [51,52], Yua austro-orientalis [31], Y. chinensis [31]
T. obtectum [51,52], T. retinervum [51], T. serrulatum [52], T. sichouense [52]V. Viteae

(32/190)
Ampelocissus Planch.

(13/115)
Undefined-18-Cayratia geniculata [31], Cissus antarctica [31], C. barbeyana [40], C. bosseri [40], C. cactiformis [40], C. descoingsii, [31,41], C. diffusiflora [40], C. floribunda [40], C. hastata [40], C. leucophlea [40], C. repens [40], C. subtetragona [40], T. delavayi [52], T. rumicispermum [31,51,52], T. thorsborneorum [52], T. xishuangbannaense [31,52], V. brandoniana [54], V. rostrata [54]Ampelocissus acapulcensis [30], A. bombycina [30], A. bravoi [42], A. cavicaulis [30], A. erdvendbergiana [30], A. grantii [30], A. javalensis [30,42], A. latifolia [30], A. macrocirrha [30], A. martinii [42], A. obtusata [30], A. ochracea [30], A. robinsonii [30]
 Vitis L.

(19/75)
Vitis aestivalis [55], V. amurensis [45,56], V. brandoniana [54], V. cinerea [57], V. eolabrusca [54], V. flexuosa [54], V. grayensis [58], V. labrusca [45,54,59], V. lanatoides [58], V. latisulcata [58], V. palmata [60], V. pseudorotundifolia [54], V. rostrata [54], V. rotundifolia [31,41,54], V. rupestris [45], V. tiliifolia [61], V. tsoi [31,41], V. vulpina [59,62], V. wilsoniae [31,41]
 
Table 3

 

Figure 1. A summary of tThe models found for the description and quantification of seed shape in the Vitaceae. G I, G II and G III are lenses, superellipses and elongatedimages of seeds of waterCissus sterculiifolia drops[31], respectively;Tetrastigma petraeum G[51] IV, G V and GCissus quadrangularis VI[44] correspond to water drops, heart curves and elongated heart curves , respectively; G VII contains four models corresponding to other elongated curves; G VIII presents an example of the heart curves of theesemble lenses of Cayratia and Pseudocayratia types; G IX, heart curves oif the Squared Heart Curves (SqHCs) type in Ampelocissus and broadened models of Ampelocissus and Ampelopsis, and G X, Elongated Superellipse-Heart Curves (ESHCs), frequent in Tetrastigma snt pecies and observed also in Cissus sopecies and R. rhomboidea. Labelled as M7 and M6 are two models used in the description of seeds of grapetions. varieties and as precursors for other models[27][28].

 

In general, the distribution of morphological types is not in close agreement with the current taxonomic classification; nevertheless, some results may be summarized in this aspect. First, the seeds of the Elongated Superellipse-Heart Curves (ESHCs) type (Group X) are more frequent in Tetrastigma and have been observed in Rhoicissus and Cissus, but not in species of other genera. While many seeds in species of Ampelopsis, Parthenocissus and Vitis share the typical shapes of water drop and heart curves, the squared heart curve (SqHC) type (Group IX) has been predominantly observed in Ampelocissus and Ampelopsis. A number of species remain undefined due to one of these two reasons: First, their irregular seed shape making difficult the identification of an adequate model (Cayratia geniculata, Cissus antarctica) and, second, the seed images have geometric shapes but the identification of the model with the corresponding equation is pending (Tetrastigma delavayi, T. rumicispermum). In addition, further work will be done on the seeds of Vitis species.