a bit of botany : 1 / the plant

 

 In this first page, we are studying the type of the Begonia (terrestrial or epiphytic), its habit (rhizomatous, creeper, upright stem, etc), the consistency of the stems, the longevity (annual or perennial), and the presence or not, of tubers and bulbils.

1. support

 

terrestrial plant : about a plant who grows on the ground

on the forest floor  :

on the ground of a mountain meadow :

  • B. froebelii A. De Candolle /  Eupetalum section / Ecuador

or on rocks (saxicolous plant) :

  • B. ankaranensis Humbert /  Quadrilobaria section / Madagascar / on limestone
  • B. keraudrenae Bosser /  Erminea section / Madagascar /on gneiss
  • B. mananjebensis Humbert / Quadrilobaria section/ Madagascar / on gneiss and  lava

épiphytic plant : plant which grows often on a tree, but without being a parasite.

when the plant starts growing, its may grow from the ground (sowing or from a fallen leaf), then its climbs, hangs to a tree and frees itself from the ground ; its may too grow from the support, without a link with the ground.

  • B. longipetiolata Gilg /  Tetraphila section / Tropical Africa / epiphytic on a trunk
  • B. quadrialata Warburg subsp. quadrialata / Loasibegonia  section/ Tropical Africa / epiphytic on a trunk

some species have terrestrial individuals and epiphytic or saxicolous ones.

  • B. Madagascar sp. / Erminea section / Madagascar ( Makira Forest)  / this tuberous species grows on ground, or on trees, or rocks.

 

 2.longevity

annual plant : a plant with a short live, often a season (the rain season) : with these begonias, we can see simultaneously plants, plantlets, fruits with seeds and seedlings.

  • B. humilis Dryander /  Doratometra section / north-west of South America / annual Begonia

perennial plant : a plant which may  live several years ; most of begonias are perennial.

 

 3. stem

herbaceous stem : as a grass

  • B. roxburghii A de Candolle /  Sphenanthera section / India – Burma / plant  with herbaceous upright stems
  • B. hemsleyana JD Hooker / Platycentrum section / China / plant  with herbaceous upright stems

woody (at least at base or suffrutescent) : as wood ; many begonias have woody stems at base

  • B. henrilaportei D. Scherberich & J. Duruisseau / Nerviplacentaria section / Madagascar / woody stems at base
  • B. ferruginea Linneaus /  Casparya section / Colombia / sarmentous species, climb, which grows to 3 or 4 m high, hanging to the trees and thickets

plant without stem (or acaulescent) : some tuberous species ; leaves start direct from the tuber

  • B. Madagascar sp. / Erminea section / Madagascar (Masoala) / begonia acaulescent saxicolous

bulging stem at base (caudex) : plant with an upright stem bulging at base as a caudex

  • B. aconitifolia A. de Candolle /  Knesbeckia section / Brazil / begonia with a caudex (in cultivation)
  • B. dregei Otto & Dietrich /  Augustia section / South Africa / begonia with a caudex (in cultivation)

 

4. type

rhizomatous plant : plant with an underground or climbing rhizome  from which grow roots, stems or leaves

  • B. rex Putzeys / Platycentrum section/ India (Himalaya Piedmont) / rhizomatous species
  • B. vittariifolia N. Hallé /  Scutobegonia section/ Gabon / rhizomatous, saxicolous
  • B. carrieae Schlechtendal & Chamisso /  Gireoudia section / from Mexico to Colombia / rhizomatous (in cultivation)

upright stem  : the plant grows stems, sometimes thick, from the ground, erected with leaves.

  • B. carolineifolia Regel /  Gireoudia section / Mexico – Guatemala (in cultivation)
  • B. sericoneura Liebmann / Gireoudia section / Central Amaerica and north-west of South America / on a slope in Colombia

rhizomatous plant, with upright stems from the rhizome  : the stems with leaves start from the rhizome

  • B. buddleiifolia Linden /  Pilderia section / from Vénézuela to Peru
  • B. tengchiana Ch.I-Peng & Y.K. Chen /  Diploclinium section / Taïwan

climb : sarmentous plant sometimes woody, often climbing, sometimes creeping on ground ; it is not an epiphytic begonia and always grows from the ground

  • B. lyallii var. lyallii A. de Candolle /  Nerviplacentaria section/ Madagascar / may be 4 or 5 m size
  • B. lyallii var. lyallii A de Candolle f. masoalensis Aymonin /  Nerviplacentaria section / Madagascar (Masoala) / creeper
  • B. Equateur sp. / Gobenia section/ climbing species on mossy trunks at an altitude ok 3000 m
  • B. glabra Aublet / section Wageneria / Central America and South America  / creeper on trunks and rocks.

 

tuberous plant : plant with a tuber or a tuberous root, perennial as a  reserve ; many bégonias are tuberous ; they may grow as terrestrial, saxicolous or epiphytic.

  • B. aequatorialis L.B. Smith & B.G. Schubert / Eupetalum section / Ecuador / andean tuberous at high altitude
  • B. erminea L’Héritier /  Erminea section / Madagascar / tuberous saxicolous
  • B. betsimisaraka Humbert / section Erminea / Madagascar / tuberous on ground or epiphytic on trees
  • B. sambiranensis Humbert /  Quadrilobaria section / Madagascar / tuberous saxicolous

bulbils : small vegetal organs as  bulbs, which appear on stems, often to the petioles insertion, when the plant is going to dormancy ; they fall and do new plants in spring (in cultivation) or when the rain season arrives.

we see bulbils often on tuberous begonias ;

  • B. grandis Dryander / Diploclinium section/ China   Japan /
  • B. sutherlandii JD Hooker /  Augustia section / East and South Africa /

we may see bulbils sometimes on annual begonias

  • B. wakefieldii Gilg / Augustia section / Esat Africa / annual begonia which does bulbils  (and sometimes a tuber) before going to dormancy.

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