24 de julio de 2020

Order Thysanoptera: Interaction with flower of the Asteraceae Family

Multiple Thrips (Order Thysanoptera) seen engulfed in liquid collecting at the inner base of the petals in Dimorphotheca caulescens
Communal pollination/ feeding by this Order of Insects from Asters is well documented on iNat, but as of yet this is the 1st record of such a mass gathering/ communal feeding resulting in large scale mortality
Questions:
1.) Is this indeed a mass mortality of Thrips on this flower, or some other event (e.g. mass ovipositing in unique micro-niche [liquid collection])
1.) Is such an event among Thrips during communal feeding, such as in this instance, a common occurence?
2) Are such events restricted to just this species, Genus, or Family of flower? Equally, are they restricted to just this one geographical area (Koppie), or does it have a broader range of occurence?

Further reading:
https://www.researchgate.net/publication/318982877_Pollination_Potential_of_Thrips_Insecta_Thysanoptera_-_an_overview

Ingresado el 24 de julio de 2020 por anthonywalton anthonywalton | 1 observación | 0 comentarios | Deja un comentario

14 de junio de 2020

Summer to Winter flowering progression of Psammophytes: Sandstone Fynbos

1st:
Empodium plicatum
HYPOXIDACEAE
Root type unknown, possibly a corm as with most plants in Family Hypoxidaceae
Grows in sandy soils, in flatlands where vegetation is fairly sparse
First flower - April 16 2020

2nd:
Oxalis polyphylla
OXALIDACEAE
Shorter roots than other Oxalis, lacks long taproot with secondary thickening. Contains adventitious/ lateral roots
Grows in sandy soil, often near base of rocks
Oxalis commutata
OXALIDACEAE
Long taproot with secondary cortex thickening
Grows only in highly sandy deposits at base of rocks and next to paths
First flower - April 22 2020
Oxalis punctata
OXALIDACEAE
Root type unknown, possibly adventitious like O. polyphylla
Grows on boulders, in shallow sand/ silt hollows

3rd:
Albuca fragrans
ASPARAGACEAE
Root type unknown, possibly a taproot
Grows on shallow rocky flats, at higher altitudes
First flower - April 22 2020

4th:
Lachenalia punctata
ASPARAGACEAE
Root type unknown, possibly a taproot
Grows in highly sandy deposits at base of rocks and next to paths
First flower - April 23 2020

5th:
Euphorbia tuberosa
EUPHORBIACEAE
Root type unknown but likely tuberous as per species name
Grows in varying altitudes, in sandy to silty sand soils in undulating terrain with sparse vegetation, usually present near rocky areas
First flower - May 3 2020

6th:
ASTERACEAE
Senecio, Cullumia

ANALYSIS//

Ingresado el 14 de junio de 2020 por anthonywalton anthonywalton | 7 observaciones | 0 comentarios | Deja un comentario

23 de mayo de 2020

Life stage and flowering of Stachys aethiopica

1st observation:
Peak of basalt, Karoo-dolerite buttress, KZN
Specimen features
*Plant in flower
*Small, tufted herb, very short, with a basal coverage of only 5 -10 cm's (Primary growth completed?)
*No sign of secondary growth (elongation)
*Plant growing in exposed, fire-prone area

2nd observation:
Rocky, undulating slopes, Cape Sandstone, Western Cape
Specimen features
*Plant in flower
*Plant > 30 cm in height, with well defined internodes. Leaves and flowers in well-defined whorls and plant has a scrambling habit, depending partially on other plants in the scrub for support.
*Plant has completed secondary growth
*Plant growing under rocky ledge, surrounded by scrub. Unexposed area but still fire prone

Notes:

This species flowers both before and after the secondary growth phase has been completed. Variables to consider in this instance would be temp and climate differences (big difference in altitudes between 2 obs), as well as species response to habitat physiognomy (1st ob - open grassland; 2nd ob - Fynbos scrub). However, it is nevertheless interesting to note that completion of secondary growth is not always a pre-condition to flowering. Furthermore, it is interesting to note that in some plants, primary growth involves thickening and leaf development only at the base (growth of basal cover), whilst secondary growth entails an elongation of the internodes and defining of the plants flower and leaf arrangement.

Ingresado el 23 de mayo de 2020 por anthonywalton anthonywalton | 2 observaciones | 0 comentarios | Deja un comentario

12 de mayo de 2020

Genus comparison: Plectranthus and Stachys (Lamiaceae)

Plectranthus (Spurflower)
*2 spur-like appendages, erect/ semi-erect, adjoined to the rim of the upper corolla tube hood
*Lack a leafy calyx at base of corolla tube

Stachys (Hedgenettles)
*Lack any appendages on the side of the upper corolla hood. Outer lower tepal lobes sometimes shrunk, superficially resemble spurs but aren't
*Very leafy calyx, immediately subtending at the base of the tube

Ingresado el 12 de mayo de 2020 por anthonywalton anthonywalton | 2 observaciones | 0 comentarios | Deja un comentario

A geographical comparison of Aloe maculata

1st observation:
Metamorphosed Cape Sandstone ledge - 1680 masl
Specimen features
*Twice to much-branched inflorescence
*Inflorescence >1 meter
*Leaves in basal rosette, becoming slightly caulescent. Withering at tips
*Growing in scattered colony of 50+ plants

2nd observation:
Cape Sandstone slopes, undulating - KZN province - 1565 masl
Specimen features
*Much-branched inflorescence
*Inflorescence >1.5 meters
*Leaves basal rosette, with variable white striations (under and upperside), withering at tips
*Growing in high density colony of >200 plants

3rd observation:
Cape Sandstone plateau - KZN province - 1340 masl
Specimen features
*Twice branched inflorescence
*Inflorescence > 1 meter
*Leaves in basal rosette, with variable white striations (under and upperside), withering at tips
*Growing in scattered colony of +- 40-50 plants

4th observation
Cape Sandstone ledge - Cape Peninsula, Western Cape Province - 210 masl
Specimen features
*Unbranched inflorescence
*Inflorescence <1 meter
*Leaves basal rosette, with variable white striations (under and upperside), withering at tips
*Growing singly or in very sparse colonies of +- 10 plants

Notes:

There seems to be a positive correlation between an increase in altitude of the habitat and an increase in the number of Aloe's in the population/ colony
Furthermore, there seems to also be a positive correlation between an increase in altitude and the height and degree of inflorescence branching, among a few other characteristics such as leaf shape (lower altitude = broader based, oval shaped leaves)
Both these correlations could be the result of: A) A gradual change in the phyto-communal makeup of the habitats with an increase in altitude (shorter, less bushy, graminoid community more prominent with increasing altitude, offering less competition). B) Slight differences in the geology, soil depth and drainage of the habitat (1st observation - medium grained sandstone, uniform deposition. 2nd observation - fine grained, impermeable sandstone, more exposed and uneven. 3rd observation - Very consolidated sandstone, undulating and slightly metamorphosed by granite), or more subtle changes in temperature as a result of increasing/ decreasing altitude C) Changes in the number and reliability of pollinators, possibly as a result of point (a)

The last point is less likely, as one would expect a higher, more branched inflorescence offering nectar rewards in greater number as the habitat becomes more bushy and the above ground leaf/ canopy coverage increases. However, it is possible that Aloe communities in higher altitude area's take advantage of less competition from dense-growing, caulescent plants by producing more branches and more flowers with a more diluted reserve of nectar thereby encouraging greater genetic dispersal in these open habitats. This remains to be confirmed

Ingresado el 12 de mayo de 2020 por anthonywalton anthonywalton | 3 observaciones | 0 comentarios | Deja un comentario

28 de abril de 2020

Plants to use for making Alcoholic Beverages

The roots of some plants contain moulds and other micro-organisms which, when added to a water infusion or watery decoction, assist in the fermentation process in order to create alcohol

Examples of indigenous South African plants used for such purposes include:
Raphionacme hirsuta
Eulophia sp.

Ingresado el 28 de abril de 2020 por anthonywalton anthonywalton | 2 observaciones | 0 comentarios | Deja un comentario

Difference between Senecio and other slender Asters

"Osteospermum more often glandular, Senecio typically has these numerous, thin parallel bracts with sharp tips"

Similarities:
Both Senecio and Osteospermum have
*Keeled upper surface of sepals
*Sepals and pedicels with glandular hairs
*Bracts tips discoloured
*Bracts tips covering the lower base of the corolla and/or parallel on either side to the lower base of corolla

The key distinguishing feature between these 2 and other genii of slender, forbe-like Asters is:
*Bract length - Senecio= bracts >1.5x the length of petals; Osteospermum, Afroaster= bracts <1x the length of petals
*Bract/ gynoecium shape - Senecio= Bulbous shaped gynoecium, and conforming bracts
*bracts non-uniformly stratified, deeply torn, and thinly overlapping in Senecio. Bracts arranged in inner and outer (well-defined) cups in Afroaster

Ingresado el 28 de abril de 2020 por anthonywalton anthonywalton | 0 comentarios | Deja un comentario

06 de enero de 2020

Protandry

Male organs (stamens) active first upon opening of flower
Towards flower senescence, stigma becomes active and stamens wither (from bottom of inf. upwards)

'Female' flowers produce the most nectar and are most attractive, so as to entice pollinators to start from the bottom and work their way up

Common in species with dense spikes

Families: Iridaceae and Asteraceae

Ingresado el 06 de enero de 2020 por anthonywalton anthonywalton | 1 observación | 0 comentarios | Deja un comentario

05 de diciembre de 2019

Genus Wahlenbergia

Genus characteristics:

  1. Scimitar shaped anthers, pressed on or near the inner petals
  2. Single or clustered capitular inflorescence
  3. Single stemmed or branching, many-leaved

Ingresado el 05 de diciembre de 2019 por anthonywalton anthonywalton | 0 comentarios | Deja un comentario

04 de diciembre de 2019

Monoecious species

Pelargonium myrrhifolium

Ingresado el 04 de diciembre de 2019 por anthonywalton anthonywalton | 1 observación | 0 comentarios | Deja un comentario