Abstract: A new species of Aloe (Asphodelaceae) in Kenya is described as A. sergoitensis L.E. Newton and compared with A. elgonica. Aloe sergoitensis differs from A. elgonica by having forked teeth along its leaf margins, less densely-flowered racemes, and coral-red flowers that are smaller than those of A. elgonica. Its leaves are longer and have a slight bluish bloom.
{"title":"Aloe sergoitensis, a New Species of Aloe (Asphodelaceae) in Kenya, with Forked Marginal Teeth on the Leaves","authors":"L. Newton","doi":"10.2985/026.025.0111","DOIUrl":"https://doi.org/10.2985/026.025.0111","url":null,"abstract":"Abstract: A new species of Aloe (Asphodelaceae) in Kenya is described as A. sergoitensis L.E. Newton and compared with A. elgonica. Aloe sergoitensis differs from A. elgonica by having forked teeth along its leaf margins, less densely-flowered racemes, and coral-red flowers that are smaller than those of A. elgonica. Its leaves are longer and have a slight bluish bloom.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"185 1","pages":"125 - 127"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77453730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. 47 accessions of the Delosperma-clade are analyzed using ITS and four chloroplast markers. With two exceptions, Frithia pulchra and Delosperma esterhuyseniae, all accessions are retrieved in a single, unsupported Delosperma s.l. clade. The main Delosperma s.str. clade is well supported and falls in three subclades, one comprising the two Mestoklema accessions, the other two mainly Delosperma accessions, but also Corpuscularia and Ectotropis. These genera are therefore subsumed under Delosperma. Trichodiadema accessions are retrieved in several places inside the Delosperma s.l. clade. The East African-Arabian Delosperma species are monophyletic if D. alpina from the Drakensberg is included; but they are not monophyletic with the species from Madagascar and Réunion. The species of the Central Plateau of southern Africa are also monophyletic and sister to the East African-Arabian species. Two new species, Delosperma heidihartmanniae and D. melepoense, are here described in the East African-Arabian clade.
{"title":"Notes on the Delosperma-Clade (Aizoaceae)","authors":"S. Liede‐Schumann, Leonard E. Newton","doi":"10.2985/026.025.0109","DOIUrl":"https://doi.org/10.2985/026.025.0109","url":null,"abstract":"Abstract. 47 accessions of the Delosperma-clade are analyzed using ITS and four chloroplast markers. With two exceptions, Frithia pulchra and Delosperma esterhuyseniae, all accessions are retrieved in a single, unsupported Delosperma s.l. clade. The main Delosperma s.str. clade is well supported and falls in three subclades, one comprising the two Mestoklema accessions, the other two mainly Delosperma accessions, but also Corpuscularia and Ectotropis. These genera are therefore subsumed under Delosperma. Trichodiadema accessions are retrieved in several places inside the Delosperma s.l. clade. The East African-Arabian Delosperma species are monophyletic if D. alpina from the Drakensberg is included; but they are not monophyletic with the species from Madagascar and Réunion. The species of the Central Plateau of southern Africa are also monophyletic and sister to the East African-Arabian species. Two new species, Delosperma heidihartmanniae and D. melepoense, are here described in the East African-Arabian clade.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"6 1","pages":"100 - 114"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82162448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Verloove, Águedo Marrero Rodríguez, M. Salas-Pascual, A. Guiggi
Abstract: Further field work in Gran Canaria (Canary Islands, Spain) yielded new records of escaped cacti. Opuntia elatior, O. engelmannii, O. phaeacantha, O. stricta, Oreocereus pseudofossulatus, Pilosocereus polygonus, Trichocereus cuzcoensis and T. pachanoi are reported for the first time from Gran Canaria. A spontaneous hybrid between two invasive species (O. ficus-indica and O. robusta) was recorded in two localities. Several of these taxa appear to be firmly established while others are considered casuals, at least at present. Austrocylindropuntia cylindrica – a species formerly considered doubtful in the Canary Islands – is confirmed from Gran Canaria. New records are presented for three recently detected, naturalized or invasive species: Cylindropuntia bigelovii, C. prolifera and Opuntia lindheimeri. All newly detected taxa are illustrated and a key for the identification of the opuntioid species reliably recorded so far in the Canary Islands is presented.
{"title":"New Cactus Records from Gran Canaria with a Key to the Opuntioid Species Now Established in the Canary Islands (Spain)","authors":"F. Verloove, Águedo Marrero Rodríguez, M. Salas-Pascual, A. Guiggi","doi":"10.2985/026.025.0110","DOIUrl":"https://doi.org/10.2985/026.025.0110","url":null,"abstract":"Abstract: Further field work in Gran Canaria (Canary Islands, Spain) yielded new records of escaped cacti. Opuntia elatior, O. engelmannii, O. phaeacantha, O. stricta, Oreocereus pseudofossulatus, Pilosocereus polygonus, Trichocereus cuzcoensis and T. pachanoi are reported for the first time from Gran Canaria. A spontaneous hybrid between two invasive species (O. ficus-indica and O. robusta) was recorded in two localities. Several of these taxa appear to be firmly established while others are considered casuals, at least at present. Austrocylindropuntia cylindrica – a species formerly considered doubtful in the Canary Islands – is confirmed from Gran Canaria. New records are presented for three recently detected, naturalized or invasive species: Cylindropuntia bigelovii, C. prolifera and Opuntia lindheimeri. All newly detected taxa are illustrated and a key for the identification of the opuntioid species reliably recorded so far in the Canary Islands is presented.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"30 1","pages":"115 - 124"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81560369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Siebert, Janine Steytler, R. Boneschans, F. Siebert, M. Coetzee
Abstract: Very little is known about the relations between aloes and soil metals, despite evidence that aloes often form dense populations on metalliferous soils. This study targeted eight rock outcrops where aloes dominated the vegetation to determine whether these succulents have a preference for soils rich in heavy metals and whether they accumulate any of these metals in their leaf tissue. Soil analyses suggested that densely populated rock outcrops are rarely characterised by high concentrations of heavy metals. Analyses of leaf material revealed no metal hyperaccumulators, with most species acting as excluders of most metals. The only metals to be reflected in leaf material to some degree across populations were copper (mean of 4 µg g-1), iron (mean of 208 µg g-1), manganese (mean of 342 µg g-1) and zinc (mean of 31 µg g-1)(all values are based on leaf dry weight). Aloe greatheadii plants from the ultramafic-peralkaline Koedoesfontein Complex in the Vredefort Dome contained the highest concentrations of Mn (558 µg g-1) and were subjected to further sampling across four geological substrates to determine the limits of its accumulation ability (mean of 855 µg g-1 on wehrlite). This aloe was found to be non-hyperaccumulating, but tolerant to elevated Mn concentrations in its tissue. The uptake of Mn from the soil was not so much influenced by soil available Mn, but rather by decreasing pH, and increasing electric conductivity and soil potassium.
{"title":"Manganese Tolerance of Aloe greatheadii Schönland var. davyana (Schönland) Glen & D.S.Hardy (Asphodelaceae: Alooideae) on Ultramafic-Peralkaline Outcrops, South Africa","authors":"S. Siebert, Janine Steytler, R. Boneschans, F. Siebert, M. Coetzee","doi":"10.2985/026.025.0108","DOIUrl":"https://doi.org/10.2985/026.025.0108","url":null,"abstract":"Abstract: Very little is known about the relations between aloes and soil metals, despite evidence that aloes often form dense populations on metalliferous soils. This study targeted eight rock outcrops where aloes dominated the vegetation to determine whether these succulents have a preference for soils rich in heavy metals and whether they accumulate any of these metals in their leaf tissue. Soil analyses suggested that densely populated rock outcrops are rarely characterised by high concentrations of heavy metals. Analyses of leaf material revealed no metal hyperaccumulators, with most species acting as excluders of most metals. The only metals to be reflected in leaf material to some degree across populations were copper (mean of 4 µg g-1), iron (mean of 208 µg g-1), manganese (mean of 342 µg g-1) and zinc (mean of 31 µg g-1)(all values are based on leaf dry weight). Aloe greatheadii plants from the ultramafic-peralkaline Koedoesfontein Complex in the Vredefort Dome contained the highest concentrations of Mn (558 µg g-1) and were subjected to further sampling across four geological substrates to determine the limits of its accumulation ability (mean of 855 µg g-1 on wehrlite). This aloe was found to be non-hyperaccumulating, but tolerant to elevated Mn concentrations in its tissue. The uptake of Mn from the soil was not so much influenced by soil available Mn, but rather by decreasing pH, and increasing electric conductivity and soil potassium.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"30 1","pages":"91 - 99"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80031989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: In preparation for a monograph of Euphorbia in southern Africa, twelve new taxa are described. In Euphorbia subsect. Medusea (Haw.) Pax & K. Hoffm. one new species, E. willowmorensis Bruyns and three new subspecies, E. arida subsp. camdebooensis Bruyns, E. friedrichiae subsp. pofadderensis Bruyns and E. multiceps subsp. tanquana Bruyns are described; two new subspecies, E. ferox subsp. calitzdorpensis Bruyns and E. pseudoglobosa subsp. vlokii Bruyns are described in Euphorbia ser. Meleuphorbia (A.Berger) Bruyns; one new subspecies, Euphorbia patula subsp. brucebayeri Bruyns is described in Euphorbia subsect. Dactylanthes (Haw.) Pax & K.Hoffm. In Euphorbia sect. Articulofruticosae Bruyns one new subspecies, E. ephedroides subsp. gamsbergensis Bruyns is described. In Euphorbia sect. Esula (Pers.) Dumort. one new species, E. corneliae Bruyns, is described from southern Namibia. In Euphorbia sect. Euphorbia there are one new species, E. otavibergensis Bruyns; one new subspecies E. subsalsa subsp. otzenii Bruyns; and one new variety, E. lydenburgensis var. minor Bruyns. In addition, in subsect. Dactylanthes the concept of Euphorbia patula Mill. is substantially re-configured and four subspecies are recognized, with E. anacantha Aiton and E. wilmaniae Marloth included as two of these subspecies.
摘要:为编写非洲南部大戟属植物专著，介绍了12个新分类群。属大戟亚科。Medusea(山楂)。Pax & K. Hoffm。新种1个;新亚种3个;camdebooensis Bruyns, E. friedrich亚科;牛蹄草和多头牛蹄草亚种。tanquana Bruyns被描述;二新亚种;花楸属和假球状花楸属亚属。vlokii Bruyns在Euphorbia ser中有描述。布鲁恩斯;一新亚种，大戟亚。brucebayeri Bruyns在大戟属亚科中有描述。Dactylanthes(山楂)。帕克斯& k .霍夫曼。在大戟科中，细果科Bruyns一新亚种，麻黄属亚种。描述了gamsbergensis Bruyns。源自大戟科。Esula (Pers)Dumort。在纳米比亚南部发现了一种新种，即E. corneliae Bruyns。大戟科大戟属有一新种(E. otavibergensis Bruyns);一新亚种沙沙沙沙。otzenii Bruyns;和一个新变种，lydenburgensis var. minor Bruyns。此外，在分节中。Dactylanthes大戟的概念。其中，anacantha Aiton和E. wilmaniae Marloth是其中的两个亚种。
{"title":"New Taxa in Euphorbia (Euphorbiaceae) in Southern Africa","authors":"P. Bruyns","doi":"10.2985/026.025.0104","DOIUrl":"https://doi.org/10.2985/026.025.0104","url":null,"abstract":"Abstract: In preparation for a monograph of Euphorbia in southern Africa, twelve new taxa are described. In Euphorbia subsect. Medusea (Haw.) Pax & K. Hoffm. one new species, E. willowmorensis Bruyns and three new subspecies, E. arida subsp. camdebooensis Bruyns, E. friedrichiae subsp. pofadderensis Bruyns and E. multiceps subsp. tanquana Bruyns are described; two new subspecies, E. ferox subsp. calitzdorpensis Bruyns and E. pseudoglobosa subsp. vlokii Bruyns are described in Euphorbia ser. Meleuphorbia (A.Berger) Bruyns; one new subspecies, Euphorbia patula subsp. brucebayeri Bruyns is described in Euphorbia subsect. Dactylanthes (Haw.) Pax & K.Hoffm. In Euphorbia sect. Articulofruticosae Bruyns one new subspecies, E. ephedroides subsp. gamsbergensis Bruyns is described. In Euphorbia sect. Esula (Pers.) Dumort. one new species, E. corneliae Bruyns, is described from southern Namibia. In Euphorbia sect. Euphorbia there are one new species, E. otavibergensis Bruyns; one new subspecies E. subsalsa subsp. otzenii Bruyns; and one new variety, E. lydenburgensis var. minor Bruyns. In addition, in subsect. Dactylanthes the concept of Euphorbia patula Mill. is substantially re-configured and four subspecies are recognized, with E. anacantha Aiton and E. wilmaniae Marloth included as two of these subspecies.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"41 1","pages":"35 - 56"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80190468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: The identity of Astroloba pentagona (Haw.) Uitewaal (Asphodelaceae: Alooideae), the type species of the genus Astroloba Uitewaal, is clarified. It is shown that the name A. pentagona can be applied to populations of Astroloba from north of the Swartberg Mountains in the Western Cape Province of South Africa. The history of the name A. pentagona is discussed, and the description of the species is amplified. An epitype is designated and a geographical distribution map is provided for the species.
{"title":"The Identity and Typification of Astroloba pentagona (Haw.) Uitewaal (Asphodelaceae: Alooideae), the Type Species of the Genus Astroloba Uitewaal","authors":"S. Molteno, Gideon F. Smith","doi":"10.2985/026.025.0105","DOIUrl":"https://doi.org/10.2985/026.025.0105","url":null,"abstract":"Abstract: The identity of Astroloba pentagona (Haw.) Uitewaal (Asphodelaceae: Alooideae), the type species of the genus Astroloba Uitewaal, is clarified. It is shown that the name A. pentagona can be applied to populations of Astroloba from north of the Swartberg Mountains in the Western Cape Province of South Africa. The history of the name A. pentagona is discussed, and the description of the species is amplified. An epitype is designated and a geographical distribution map is provided for the species.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"15 1","pages":"57 - 71"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72531653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: The early nomenclature and typification of the name Aloe ferox Mill. (Asphodelaceae: Alooideae) is discussed and clarified. It is shown that a plate included in Munting (1727) is the lectotype of the name; we also designate an epitype. A previous neotypification of the name A. ferox was redundant.
{"title":"The Nomenclature of Aloe ferox Mill. (Asphodelaceae: Alooideae), an Iconic Medium-Sized to Large Aloe from Southern South Africa","authors":"Gideon F. Smith, E. Figueiredo","doi":"10.2985/026.025.0112","DOIUrl":"https://doi.org/10.2985/026.025.0112","url":null,"abstract":"Abstract: The early nomenclature and typification of the name Aloe ferox Mill. (Asphodelaceae: Alooideae) is discussed and clarified. It is shown that a plate included in Munting (1727) is the lectotype of the name; we also designate an epitype. A previous neotypification of the name A. ferox was redundant.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"4 1","pages":"128 - 132"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88471351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: A new species of Kalanchoe Adans. (Crassulaceae), K. crouchii Gideon F.Sm. & Figueiredo, is described from the Wolkberg Centre of Endemism, Mpumalanga Province, South Africa. The species is allied to K. luciae Raym.-Hamet, K. montana Compton, K. thyrsiflora Harv., and K. winteri Gideon F.Sm., N.R.Crouch & Mich.Walters, from which it can be readily separated on vegetative and reproductive characteristics.
{"title":"Kalanchoe crouchii Gideon F.Sm. & Figueiredo (Crassulaceae), a New Species from the Dolomites of the Wolkberg Centre of Endemism, Mpumalanga Province, South Africa","authors":"Gideon F. Smith, E. Figueiredo","doi":"10.2985/026.025.0107","DOIUrl":"https://doi.org/10.2985/026.025.0107","url":null,"abstract":"Abstract: A new species of Kalanchoe Adans. (Crassulaceae), K. crouchii Gideon F.Sm. & Figueiredo, is described from the Wolkberg Centre of Endemism, Mpumalanga Province, South Africa. The species is allied to K. luciae Raym.-Hamet, K. montana Compton, K. thyrsiflora Harv., and K. winteri Gideon F.Sm., N.R.Crouch & Mich.Walters, from which it can be readily separated on vegetative and reproductive characteristics.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"19 1","pages":"84 - 90"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80969449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: A synopsis of the infrageneric classification of Astroloba Uitewaal (Asphodelaceae: Alooideae) is presented, and the 12 known species are assigned to two subgenera. Poellnitzia Uitewaal is reduced to subgenus rank in Astroloba, as A. subg. Poellnitzia (Uitewaal) Molteno & Gideon F.Sm., and three sections within A. subg. Astroloba, A. sect. Intercedens Molteno & Gideon F.Sm., A. sect. Inflata Molteno & Gideon F.Sm., and A. sect. Vastora Molteno & Gideon F.Sm., are recognised, all of which are described here. A new combination, A. spirella (Haw.) Molteno & Gideon F.Sm. based on Haworthia spirella Haw., is published here. An epitype is designated for this combination. The accepted species that are included in the infrageneric groupings are enumerated, along with an indication of their typification. Separate keys are provided to the subgenera, sections and species recognised in Astroloba.
{"title":"A Synopsis of Astroloba Uitewaal (Asphodelaceae: Alooideae): Species, Types, and Infrageneric Classification","authors":"S. Molteno, Gideon F. Smith, E. Figueiredo","doi":"10.2985/026.025.0106","DOIUrl":"https://doi.org/10.2985/026.025.0106","url":null,"abstract":"Abstract: A synopsis of the infrageneric classification of Astroloba Uitewaal (Asphodelaceae: Alooideae) is presented, and the 12 known species are assigned to two subgenera. Poellnitzia Uitewaal is reduced to subgenus rank in Astroloba, as A. subg. Poellnitzia (Uitewaal) Molteno & Gideon F.Sm., and three sections within A. subg. Astroloba, A. sect. Intercedens Molteno & Gideon F.Sm., A. sect. Inflata Molteno & Gideon F.Sm., and A. sect. Vastora Molteno & Gideon F.Sm., are recognised, all of which are described here. A new combination, A. spirella (Haw.) Molteno & Gideon F.Sm. based on Haworthia spirella Haw., is published here. An epitype is designated for this combination. The accepted species that are included in the infrageneric groupings are enumerated, along with an indication of their typification. Separate keys are provided to the subgenera, sections and species recognised in Astroloba.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"5 1","pages":"72 - 83"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78680328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Most cacti in subfamily Cactoideae have a thick cortex vascularized by a network of cortical bundles. It was noticed that some cortical bundles had a leaf-like feature: clusters of terminal tracheids. The objective of this research was to examine a range of species and characterize the clusters. Of the 226 species examined in 85 genera, 105 (46.7%) had clusters of terminal tracheids. Species with clusters were widely distributed throughout the subfamily. A few genera were uniform, with all sampled species having clusters (Ariocarpus, Corryocactus) or with all sampled species lacking them (Armatocereus, Mammillaria, Melocactus). Most genera were variable (e. g., Cereus, Cleistocactus) having some species with terminal tracheid clusters and other species lacking them. Where present, the clusters consisted of short, broad tracheids (not vessel elements), one or several phloem poles, but never fibers or sclereids (except Strombocactus disciformis). Clusters were most likely to occur at the apex of a rib or tubercle, especially near an areole; they often also occurred along the face of a rib; they were least common at the sinuses between ribs. Without exception, they occurred within the palisade cortex or along its base but never deep within the cortex. No ecological or functional role was obvious.
{"title":"Many Cacti Have Clusters of Terminal Tracheids on Their Cortical Bundles","authors":"J. Mauseth","doi":"10.2985/026.024.0101","DOIUrl":"https://doi.org/10.2985/026.024.0101","url":null,"abstract":"Abstract: Most cacti in subfamily Cactoideae have a thick cortex vascularized by a network of cortical bundles. It was noticed that some cortical bundles had a leaf-like feature: clusters of terminal tracheids. The objective of this research was to examine a range of species and characterize the clusters. Of the 226 species examined in 85 genera, 105 (46.7%) had clusters of terminal tracheids. Species with clusters were widely distributed throughout the subfamily. A few genera were uniform, with all sampled species having clusters (Ariocarpus, Corryocactus) or with all sampled species lacking them (Armatocereus, Mammillaria, Melocactus). Most genera were variable (e. g., Cereus, Cleistocactus) having some species with terminal tracheid clusters and other species lacking them. Where present, the clusters consisted of short, broad tracheids (not vessel elements), one or several phloem poles, but never fibers or sclereids (except Strombocactus disciformis). Clusters were most likely to occur at the apex of a rib or tubercle, especially near an areole; they often also occurred along the face of a rib; they were least common at the sinuses between ribs. Without exception, they occurred within the palisade cortex or along its base but never deep within the cortex. No ecological or functional role was obvious.","PeriodicalId":50413,"journal":{"name":"Haseltonia","volume":"57 1","pages":"64 - 74"},"PeriodicalIF":1.5,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83683159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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