"Aloe plicatilis " presents an unusual combination of features among Aloes ( arborescent, with trunk branched dichotomously at short intervals, distichous leaves in the mature plant, straight perianth with the inner segments free ) so taxonomists have in the past assign it to its own separate sub-genus " Kumara " within the genus Aloe.
42.
The habit of " climbing palm " is one of the terms used for referring to the diversity of habits of palm stems, the rest are " arborescent palms " or tree palms, " shrub palms " and " acaulescent palms ", as defined in Dransfield ( 1978 cited in Kubitzki ed . 1998, see also Uhl & Dransfield 1987 " Genera Palmarum " ).
43.
The shape of the tentacles is generally adapted to the diet, and to the size of the particles to be ingested : the filter-feeding species mostly have complex arborescent tentacles, intended to maximize the surface area available for filtering, while the species feeding on the substratum will more often need digitate tentacles to sort out the nutritional material; the detritivore species living on fine sand or mud more often need shorter " peltate " tentacles, shaped like shovels.
44.
Likewise, where competition for resources is more competitive " both in the number of species and the height of surrounding plants " there are times when it is to the advantage of a plant to develop into arborescent, dendroid trees . This development is because these particular " Pachypodium " must compete with other plants for resources in a dry deciduous forest, composed of, perhaps, arborescent " Aloe ", members of the Didiereaceae genera "-- Alluaudia, Alluaudiopsis, Decaryia, and Didierea; all endemic to Madagascar-- " and " Uncarina " species, for instance.
45.
Likewise, where competition for resources is more competitive " both in the number of species and the height of surrounding plants " there are times when it is to the advantage of a plant to develop into arborescent, dendroid trees . This development is because these particular " Pachypodium " must compete with other plants for resources in a dry deciduous forest, composed of, perhaps, arborescent " Aloe ", members of the Didiereaceae genera "-- Alluaudia, Alluaudiopsis, Decaryia, and Didierea; all endemic to Madagascar-- " and " Uncarina " species, for instance.
46.
Mazon Creek flora includes : lycopsids, related to modern club moss, with arborescent forms named " Lepidophloios ", " Sigillaria " and " Lepidodendron ", and herbaceous forms called " Lycopodites " and " Cormophyton "; sphenopsids like " Calamites " a tree-like horsetail relative, with common foliage names of " Annularia " and " Asterophyllites ", and a vine-like form called " Sphenophyllum "; Pteridophyta as marattitalean tree ferns and Filicales and Zygopteridales understory ferns, with common foliage names of " Pecopteris ", " Acitheca " and " Lobatopteris "; pteridosperms, also known as seed ferns, an extinct group of plants that grew both as trees and smaller shrubs, with features like pinnated leaves similar to true ferns, but reproduced by seeds instead of spores; they had common foliage names " Mariopteris ", " Alethopteris ", " Odontopteris ", " Neuropteris ", " Laveineopteris " and " Macroneuropteris "; extinct gymnosperm " Cordaites ", believed to be closely related to and sharing many features with modern conifers.
