Hakea sericea vs Hakea decurrens: an attempt to find reliable observations on iNaturalist

Research Grade:

• Geographic distribution of Research Grade observations of Hakea sericea in Australia:
  https://www.inaturalist.org/observations?place_id=6744&quality_grade=research&subview=map&taxon_id=321137
  Many RG observations around Sydney and Camberra, where there are no RG observations of Hakea decurrens physocarpa.

• Geographic distribution of Research Grade observations of Hakea decurrens physocarpa in Australia:
  https://www.inaturalist.org/observations?place_id=6744&quality_grade=research&subview=map&taxon_id=709820
  Some RG observations in the southeast coast between the Wilsons Promontory and Cape Howe, where there are no RG observations of Hakea sericea.

Without the RG requirement:
https://www.inaturalist.org/observations?place_id=6744&subview=map&taxon_id=321137
https://www.inaturalist.org/observations?place_id=6744&subview=map&taxon_id=709820
Significant overlap, with the same major difference:

• around Sydney and all the way south to Canberra and Nowra: Hakea sericea but not Hakea decurrens physocarpa;
• between the Wilsons Promontory and Cape Howe: Hakea decurrens physocarpa but not Hakea sericea.

Hakea decurrens (any subspecies), Research grade:
https://www.inaturalist.org/observations?place_id=6744&quality_grade=research&subview=map&taxon_id=320929

• some scattered observations around Sydney and Camberra;
• more observations in the SE, where there are no RG observations of Hakea sericea.

Places where only Hakea sericea is found:

• Greater Sydney Area, NS, AU (51 RG observations)
  https://www.inaturalist.org/observations?place_id=142327&quality_grade=research&subview=map&taxon_id=148286&view=species

• Hornsby - North, NS, AU (4 RG observations)
  https://www.inaturalist.org/observations?place_id=49026&quality_grade=research&subview=map&taxon_id=148286&view=species

• Wollondilly, NS, AU (2 RG observations)
  https://www.inaturalist.org/observations?place_id=49068&quality_grade=research&subview=map&taxon_id=148286&view=species

Places where only Hakea decurrens is found:

• South Gippsland - East, VI, AU (8 RG observations)
  https://www.inaturalist.org/observations?place_id=14734&quality_grade=research&subview=map&taxon_id=148286&view=species

• E. Gippsland - Orbost, VI, AU (7 RG observations)
  https://www.inaturalist.org/observations?place_id=48848&quality_grade=research&subview=map&taxon_id=148286&view=species

• Wellington - Alberton, VI, AU (1 RG observation)
  https://www.inaturalist.org/observations?place_id=48864&quality_grade=research&subview=map&taxon_id=148286&view=species

Some RG observations of Hakea sericea in the Greater Sydney Area with more than 2 IDs:

• https://www.inaturalist.org/observations/31367730 (very similar to ours; thick leaves at almost 90 degrees to stem, pedicels tinged pink)
• https://www.inaturalist.org/observations/53451035 (rather similar to ours)
• https://www.inaturalist.org/observations/30595190 (moderately similar to ours: leaves thinner but perpendicular to stem; pedicels seem too long)
• https://www.inaturalist.org/observations/66690778 (single photo, not quite similar to ours: leaves thinner at 45 degrees to stem; pedicel seems longer; one strong similarity, however: new leaves grow together and only spread after reaching a considerable length)
• https://www.inaturalist.org/observations/24923696 (same about the leaves)
• https://www.inaturalist.org/observations/57437059 (rather similar to ours but the pedicels seem longer and their hairs are not appressed)

Some RG observations of Hakea decurrens physocarpa in E. Gippsland - Orbost / South Gippsland - East / Wellington - Alberton (never with more than 2 IDs):

• https://www.inaturalist.org/observations/19093583 (leaves much thinner and sparse than around Lousã - always perpendicular to the stem, even the newest leaves close to the extremity of the branch, unlike what we see around Lousã where the new leaves grow together and only spread after reaching a considerable length)
• https://www.inaturalist.org/observations/19096478 (same)
• https://www.inaturalist.org/observations/19329843 (same)
• https://www.inaturalist.org/observations/46949086 (same, so much so that some of the leaves even turn slightly backwards)
• https://www.inaturalist.org/observations/46949274 (same)
• https://www.inaturalist.org/observations/46940926 (same, and the flowers are intensely pink)
• https://www.inaturalist.org/observations/46942337 (same, althouth the pink colour is less intense)
• https://www.inaturalist.org/observations/14771634 (same)

Judging from these observations, reinforced by those from South Africa, I still think that the species observed around Lousã is probably Hakea sericea rather than Hakea decurrens ssp. physocarpa. The leaves are not always perpendicular to the stem, quite the contrary, as can be seen in these observations (among many others):

• https://www.inaturalist.org/observations/76525351
• https://www.inaturalist.org/observations/76525171
• https://www.inaturalist.org/observations/76475242
• https://www.inaturalist.org/observations/75305776
• https://www.inaturalist.org/observations/74611628

Publicado el 10 de mayo de 2021 por mferreira