Photo 74441408, (c) J. Richard Abbott, some rights reserved (CC BY-NC), uploaded by J. Richard Abbott

Attribution © J. Richard Abbott
some rights reserved
Uploaded by jrichardabbott jrichardabbott
Source iNaturalist
Associated observations

Photos / Sounds

What

Purple Cudweed (Gamochaeta purpurea)

Observer

jrichardabbott

Date

May 21, 2020

Description

adjacent to the south side of the Botanical Research Building (Sundell Herbarium), came up in small area that was previously clover-dominated lawn, protected from mowing this year. 3 Gamochaeta species growing intermixed in this one small area; all 3 also seen scattered around campus, along with 2 other Gamochaeta species (before the soil dried enough for mowing to re-commence). the last photo shows this species adjacent to 3 other species, for comparison. for positive ID, it is necessary to study some very tiny & subtle features, e.g., the next to last photo is a poor attempt to capture the swollen glassy hair bases on the upper leaf surface, a feature diagnostic for this species -- some of the clusters of 3-5 tiny bright spots are differential reflections from the round glassy pustules (swellings at the hair bases), which i could see clearly through my microscope but not so well in this pic, although having seen them through the microscope my brain at least pretends that some of the larger circles at the base of some of the hairs are the swellings. this species looks a lot like G. argyrinea but (in addition to the adaxial pustular hair bases) has more triangular inner phyllaries with narrowly acute tips & involucres ~4-4.5 mm long. voucher JRA 28156

Sizes